Subjects -> BIOLOGY (Total: 3491 journals)
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BIOLOGY (1673 journals)                  1 2 3 4 5 6 7 8 | Last

Showing 1 - 200 of 1720 Journals sorted alphabetically
AAPS Journal     Hybrid Journal   (Followers: 31)
Achievements in the Life Sciences     Open Access   (Followers: 8)
ACS Pharmacology & Translational Science     Hybrid Journal   (Followers: 2)
ACS Synthetic Biology     Hybrid Journal   (Followers: 31)
Acta Biologica Colombiana     Open Access   (Followers: 7)
Acta Biologica Hungarica     Full-text available via subscription   (Followers: 5)
Acta Biologica Sibirica     Open Access   (Followers: 2)
Acta Biologica Turcica     Open Access   (Followers: 1)
Acta Biologica Venezuelica     Open Access  
Acta Biomaterialia     Hybrid Journal   (Followers: 30)
Acta Biotheoretica     Hybrid Journal   (Followers: 3)
Acta Chiropterologica     Full-text available via subscription   (Followers: 6)
acta ethologica     Hybrid Journal   (Followers: 4)
Acta Fytotechnica et Zootechnica     Open Access   (Followers: 1)
Acta Limnologica Brasiliensia     Open Access   (Followers: 4)
Acta Médica Costarricense     Open Access   (Followers: 2)
Acta Musei Silesiae, Scientiae Naturales     Open Access   (Followers: 3)
Acta Neurobiologiae Experimentalis     Open Access  
Acta Parasitologica     Hybrid Journal   (Followers: 12)
Acta Scientiae Biological Research     Open Access   (Followers: 1)
Acta Scientiarum. Biological Sciences     Open Access   (Followers: 2)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis     Open Access   (Followers: 1)
Actualidades Biológicas     Open Access   (Followers: 1)
Advanced Biosystems     Hybrid Journal  
Advanced Health Care Technologies     Open Access   (Followers: 10)
Advanced Journal of Graduate Research     Open Access   (Followers: 1)
Advanced Nonlinear Studies     Hybrid Journal  
Advanced Quantum Technologies     Hybrid Journal  
Advanced Studies in Biology     Open Access   (Followers: 1)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 2)
Advances in Bioinformatics     Open Access   (Followers: 20)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4)
Advances in Biology     Open Access   (Followers: 12)
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 8)
Advances in Cell Biology/ Medical Journal of Cell Biology     Open Access   (Followers: 30)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 14)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 14)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 7)
Advances in Ecological Research     Full-text available via subscription   (Followers: 44)
Advances in Environmental Sciences - International Journal of the Bioflux Society     Open Access   (Followers: 19)
Advances in Enzyme Research     Open Access   (Followers: 12)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 9)
Advances in Genome Biology     Full-text available via subscription   (Followers: 11)
Advances in High Energy Physics     Open Access   (Followers: 23)
Advances in Human Biology     Open Access   (Followers: 5)
Advances in Life Science and Technology     Open Access   (Followers: 20)
Advances in Life Sciences     Open Access   (Followers: 7)
Advances in Marine Biology     Full-text available via subscription   (Followers: 21)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 26)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 7)
Advances in Structural Biology     Full-text available via subscription   (Followers: 6)
Advances in Tropical Biodiversity and Environmental Sciences     Open Access   (Followers: 3)
Advances in Virus Research     Full-text available via subscription   (Followers: 6)
Adversity and Resilience Science : Journal of Research and Practice     Hybrid Journal   (Followers: 3)
African Journal of Range & Forage Science     Hybrid Journal   (Followers: 12)
AFRREV STECH : An International Journal of Science and Technology     Open Access   (Followers: 3)
Ageing Research Reviews     Hybrid Journal   (Followers: 12)
Aging Cell     Open Access   (Followers: 26)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Agrokreatif Jurnal Ilmiah Pengabdian kepada Masyarakat     Open Access  
AJP Cell Physiology     Hybrid Journal   (Followers: 18)
AJP Endocrinology and Metabolism     Hybrid Journal   (Followers: 25)
AJP Lung Cellular and Molecular Physiology     Hybrid Journal   (Followers: 3)
Al-Kauniyah : Jurnal Biologi     Open Access  
Alasbimn Journal     Open Access   (Followers: 2)
Alces : A Journal Devoted to the Biology and Management of Moose     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Biology Teacher     Full-text available via subscription   (Followers: 14)
American Fern Journal     Full-text available via subscription   (Followers: 1)
American Journal of Agricultural and Biological Sciences     Open Access   (Followers: 9)
American Journal of Bioethics     Hybrid Journal   (Followers: 17)
American Journal of Human Biology     Hybrid Journal   (Followers: 18)
American Journal of Medical and Biological Research     Open Access   (Followers: 10)
American Journal of Plant Sciences     Open Access   (Followers: 21)
American Journal of Primatology     Hybrid Journal   (Followers: 16)
American Malacological Bulletin     Full-text available via subscription   (Followers: 3)
American Naturalist     Full-text available via subscription   (Followers: 81)
Amphibia-Reptilia     Hybrid Journal   (Followers: 6)
Anadol University Journal of Science and Technology B : Theoritical Sciences     Open Access  
Anadolu University Journal of Science and Technology : C Life Sciences and Biotechnology     Open Access   (Followers: 2)
Anaerobe     Hybrid Journal   (Followers: 4)
Anales de Biología     Open Access   (Followers: 3)
Analytical Methods     Full-text available via subscription   (Followers: 13)
Anatomical Science International     Hybrid Journal   (Followers: 3)
Animal Cells and Systems     Hybrid Journal   (Followers: 5)
Animal Models and Experimental Medicine     Open Access  
Annales de Limnologie - International Journal of Limnology     Hybrid Journal   (Followers: 1)
Annales françaises d'Oto-rhino-laryngologie et de Pathologie Cervico-faciale     Full-text available via subscription   (Followers: 3)
Annales Henri Poincaré     Hybrid Journal   (Followers: 3)
Annales Universitatis Mariae Curie-Sklodowska, sectio C – Biologia     Open Access   (Followers: 1)
Annals of Applied Biology     Hybrid Journal   (Followers: 8)
Annals of Biomedical Engineering     Hybrid Journal   (Followers: 19)
Annals of Human Biology     Hybrid Journal   (Followers: 6)
Annals of Science and Technology     Open Access  
Annual Research & Review in Biology     Open Access   (Followers: 2)
Annual Review of Biomedical Engineering     Full-text available via subscription   (Followers: 15)
Annual Review of Biophysics     Full-text available via subscription   (Followers: 25)
Annual Review of Cancer Biology     Full-text available via subscription   (Followers: 4)
Annual Review of Cell and Developmental Biology     Full-text available via subscription   (Followers: 42)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 15)
Annual Review of Genomics and Human Genetics     Full-text available via subscription   (Followers: 27)
Annual Review of Phytopathology     Full-text available via subscription   (Followers: 13)
Anthropological Review     Open Access   (Followers: 23)
Antibiotics     Open Access   (Followers: 9)
Antioxidants     Open Access   (Followers: 5)
Antioxidants & Redox Signaling     Hybrid Journal   (Followers: 9)
Antonie van Leeuwenhoek     Hybrid Journal   (Followers: 5)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apidologie     Hybrid Journal   (Followers: 5)
Apmis     Hybrid Journal   (Followers: 2)
APOPTOSIS     Hybrid Journal   (Followers: 9)
Applied Biology     Open Access   (Followers: 2)
Applied Bionics and Biomechanics     Open Access   (Followers: 7)
Applied Vegetation Science     Full-text available via subscription   (Followers: 10)
Aquaculture Environment Interactions     Open Access   (Followers: 4)
Aquaculture International     Hybrid Journal   (Followers: 26)
Aquaculture Reports     Open Access   (Followers: 3)
Aquaculture, Aquarium, Conservation & Legislation - International Journal of the Bioflux Society     Open Access   (Followers: 7)
Aquatic Biology     Open Access   (Followers: 8)
Aquatic Ecology     Hybrid Journal   (Followers: 38)
Aquatic Ecosystem Health & Management     Hybrid Journal   (Followers: 16)
Aquatic Science and Technology     Open Access   (Followers: 4)
Aquatic Toxicology     Hybrid Journal   (Followers: 24)
Arabian Journal of Scientific Research / المجلة العربية للبحث العلمي     Open Access   (Followers: 1)
Archaea     Open Access   (Followers: 4)
Archiv für Molluskenkunde: International Journal of Malacology     Full-text available via subscription   (Followers: 3)
Archives of Biological Sciences     Open Access  
Archives of Microbiology     Hybrid Journal   (Followers: 10)
Archives of Natural History     Hybrid Journal   (Followers: 8)
Archives of Oral Biology     Hybrid Journal   (Followers: 3)
Archives of Virology     Hybrid Journal   (Followers: 5)
Archivum Immunologiae et Therapiae Experimentalis     Hybrid Journal   (Followers: 2)
Arctic     Open Access   (Followers: 3)
Arid Ecosystems     Hybrid Journal   (Followers: 3)
Arquivos do Instituto Biológico     Open Access   (Followers: 1)
Arquivos do Museu Dinâmico Interdisciplinar     Open Access  
Arthropod Structure & Development     Hybrid Journal   (Followers: 2)
Arthropods     Open Access   (Followers: 1)
Artificial DNA: PNA & XNA     Hybrid Journal   (Followers: 3)
Asian Bioethics Review     Full-text available via subscription   (Followers: 4)
Asian Journal of Biodiversity     Open Access   (Followers: 5)
Asian Journal of Biological Sciences     Open Access   (Followers: 3)
Asian Journal of Biology     Open Access   (Followers: 2)
Asian Journal of Biotechnology and Bioresource Technology     Open Access   (Followers: 2)
Asian Journal of Cell Biology     Open Access   (Followers: 6)
Asian Journal of Developmental Biology     Open Access   (Followers: 3)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 5)
Asian Journal of Nematology     Open Access   (Followers: 4)
Asian Journal of Poultry Science     Open Access   (Followers: 5)
Atti della Accademia Peloritana dei Pericolanti - Classe di Scienze Medico-Biologiche     Open Access  
Australian Life Scientist     Full-text available via subscription   (Followers: 2)
Australian Mammalogy     Hybrid Journal   (Followers: 8)
Autophagy     Hybrid Journal   (Followers: 4)
Avian Biology Research     Full-text available via subscription   (Followers: 6)
Avian Conservation and Ecology     Open Access   (Followers: 15)
Bacterial Empire     Open Access   (Followers: 1)
Bacteriology Journal     Open Access   (Followers: 1)
Bacteriophage     Full-text available via subscription   (Followers: 3)
Bangladesh Journal of Bioethics     Open Access  
Bangladesh Journal of Plant Taxonomy     Open Access  
Bangladesh Journal of Scientific Research     Open Access   (Followers: 1)
Batman Üniversitesi Yaşam Bilimleri Dergisi     Open Access  
Berita Biologi     Open Access   (Followers: 1)
Between the Species     Open Access   (Followers: 1)
Bio Tribune Magazine     Hybrid Journal  
BIO Web of Conferences     Open Access  
BIO-Complexity     Open Access  
Bio-Grafía. Escritos sobre la Biología y su enseñanza     Open Access  
Bio-Lectura     Open Access  
BIO-SITE : Biologi dan Sains Terapan     Open Access   (Followers: 1)
Bioanalytical Reviews     Hybrid Journal   (Followers: 2)
Biocatalysis and Biotransformation     Hybrid Journal   (Followers: 6)
BioCentury Innovations     Full-text available via subscription   (Followers: 2)
Biochemistry and Cell Biology     Hybrid Journal   (Followers: 16)
Biochimie     Hybrid Journal   (Followers: 5)
BioControl     Hybrid Journal   (Followers: 5)
Biocontrol Science and Technology     Hybrid Journal   (Followers: 8)
Biodemography and Social Biology     Hybrid Journal  
BIODIK : Jurnal Ilmiah Pendidikan Biologi     Open Access   (Followers: 1)
BioDiscovery     Open Access   (Followers: 2)
Biodiversidade e Conservação Marinha : Revista CEPSUL     Open Access  
Biodiversitas : Journal of Biological Diversity     Open Access  
Biodiversity Data Journal     Open Access   (Followers: 4)
Biodiversity Informatics     Open Access   (Followers: 1)
Biodiversity Information Science and Standards     Open Access   (Followers: 2)
Biodiversity: Research and Conservation     Open Access   (Followers: 28)
Bioedukasi : Jurnal Pendidikan Biologi FKIP UM Metro     Open Access   (Followers: 1)
Bioeksperimen : Jurnal Penelitian Biologi     Open Access  
Bioelectrochemistry     Hybrid Journal   (Followers: 1)
Bioelectromagnetics     Hybrid Journal   (Followers: 2)
Bioenergy Research     Hybrid Journal   (Followers: 3)
Bioengineering and Bioscience     Open Access   (Followers: 3)
BioEssays     Hybrid Journal   (Followers: 11)
Bioethica     Open Access   (Followers: 2)
Bioethics     Hybrid Journal   (Followers: 19)
BioéthiqueOnline     Open Access  

        1 2 3 4 5 6 7 8 | Last

Similar Journals
Journal Cover
Biological Control
Journal Prestige (SJR): 0.95
Citation Impact (citeScore): 2
Number of Followers: 7  
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1049-9644 - ISSN (Online) 1090-2112
Published by Elsevier Homepage  [3207 journals]
  • Seed treatment containing Bacillus subtilis BY-2 in combination with other
    • Abstract: Publication date: June 2019Source: Biological Control, Volume 133Author(s): Xiaojia Hu, Daniel P. Roberts, Lihua Xie, Lu Qin, Yinshui Li, Xiangsheng Liao, Peipei Han, Changbing Yu, Xing LiaoAbstractBiological control treatments for soil-borne plant pathogens must provide enhanced levels of disease suppression and consistency of control over diverse soils before they enjoy wide-spread use. Bacillus megaterium A6 and two genetically distinct B. subtilis isolates, BY-2 and Tu-100, were applied individually and in combinations as seed treatments and tested in field trials conducted at four locations with different soils for control of Sclerotinia sclerotiorum on oilseed rape. The treatment containing isolate BY-2 resulted in significant reductions in disease relative to the non-treated and formulation-only controls at all four locations. Treatments containing isolate A-6 or Tu-100 resulted in a significant decrease in disease at two locations only. There were no significant reductions in disease with treatments containing combinations of these strains relative to treatments containing strains applied individually. In plant growth promotion studies conducted in pots, the seed treatment containing isolate BY-2 combined with A6 and Tu-100 resulted in seed yield greater than the non-treated control in four of the five soils tested. The seed treatment containing isolate A-6 combined with Tu-100 significantly increased yield in one soil. No other treatment containing a single isolate, or combination of two isolates, significantly increased yield in these pot studies. Field experiments reported here indicated that seed treatment with isolate BY-2 provided consistent reduction of disease at four field locations with different soil types. Pot studies suggested that combining other Bacillus isolates with BY-2 provided the added benefit of plant growth promotion.
  • An egg parasitoid interferes with biological control of tomato leafminer
           by augmentation of Nesidiocoris tenuis (Hemiptera: Miridae)
    • Abstract: Publication date: June 2019Source: Biological Control, Volume 133Author(s): Mohammad Ali Mirhosseini, Yaghoub Fathipour, Niels Holst, Mahmoud Soufbaf, J.P. MichaudTomato leaf miner (TLM), Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a serious pest of tomato production in many parts of the world. The TLM has demonstrated capacity to evolve resistance to insecticides, and residues of these on tomato fruit pose hazards to human health, making biological control solutions an urgent priority. We assessed the biological control potential of the predatory bug Nesidiocoris tenuis (Reuter), in combination with the egg parasitoid Trichogramma brassicae Bezdenko at various release rates (0, 10 or 30 females/m2/week). Predators were released either 10 days before, or 10 days after, pest establishment. The predator lowered pest density only when it was released before the pest, but not to levels likely to retain the population below economic threshold. The parasitoid had no direct effect on pest density, but negatively affected the predator's impact on the pest, likely by reducing prey suitability and shifting feeding behavior toward more herbivory and/or cannibalism. Both pest and predator displayed negative density dependence; their population growth rates declined with increasing conspecific density. Our results indicate that N. tenuis should be augmented using a predator-in-first approach, and without simultaneous releases of egg parasitoids. Augmentation of N. tenuis will require integration with other tactics to provide adequate control of TLM, but has the potential for ancillary impacts on other tomato pests such as whiteflies and spider mites.Graphical abstractGraphical abstract for this article
  • Screening and identification of an antagonistic yeast controlling
    • Abstract: Publication date: June 2019Source: Biological Control, Volume 133Author(s): Qiru Zhang, Lina Zhao, Zongbi Li, Chao Li, Bo Li, Xiangyu Gu, Xiaoyun Zhang, Hongyin ZhangAbstractPostharvest disease of pears caused by pathogens results in great economic losses. The aim of this research was to isolate a strain of potential antagonistic yeast from soil of orchards, and to test the control efficacy against postharvest blue mold decay of pears. By molecular biological identification based on comparative sequence analysis of 5.8S rDNA gene, the antagonistic strain was identified as Wickerhamomyces anomalus. The results showed that W. anomalus significantly reduced the disease incidence and lesion diameter of blue mold of pears compared with the control in vivo. The disease incidence caused by Penicillium expansum of pears was only 5.56%, when treated with 1 × 108 cells/mL W. anomalus, compared with 100% disease incidence of the control. In vitro test showed that W. anomalus reduced the spore germination rate and germ tube length of P. expansum. Meanwhile, polyphenoloxidase (PPO), peroxidase (POD), catalase (CAT) and chitinase (CHI) activities of the pears treated by W. anomalus were significantly higher than that of the control. And the expression levels of defense-related enzymes were significantly induced by W. anomalus. All these results indicated that W. anomalus has the potential to control postharvest diseases of pears, and the mechanisms involved in inhibiting spore germination and germ tube length, induction of the activities of the defense-related enzymes of pears, and improvement of the expression levels of defense-related genes of pears.
  • Screening of locally available organic materials as substrates for
           production of Pochonia chlamydosporia in Kenya
    • Abstract: Publication date: June 2019Source: Biological Control, Volume 133Author(s): Nessie D. Luambano, Rosa H. Manzanilla-López, Stephen J. Powers, Waceke J. Wanjohi, John W. Kimenju, Rama D. NarlaAbstractPochonia chlamydosporia is a nematophagous fungus with high potential for the biological control of root-knot nematodes (Meloidogyne spp.). The fungus is commonly produced in colonised rice substrate, but non-staple and more affordable substrates may encourage the production and use of this biological control agent. An in vitro study was conducted to screen different organic materials, including green and animal manures and industrial by-products as substrates for local production of viable fungal chlamydospores. Chlamydospore yield from sugarcane filter mud, bean straw, sunn hemp, goat manure, African marigold, wild sunflower, maize cobs, and velvet beans substrates was equal to or significantly greater than production using rice (standard substrate). In addition, the percentage viability of chlamydospores produced in most organic substrates was greater than 50%. The use of non-staple substrates deserves further investigation as a viable, and economical local option to rice substrate for mass production of P. chlamydosporia inoculum in Sub-Saharan Africa.
  • The proportion of blue light affects parasitoid wasp behavior in
           LED-extended photoperiod in greenhouses: Increased parasitism and
           offspring sex ratio bias
    • Abstract: Publication date: June 2019Source: Biological Control, Volume 133Author(s): Précillia Cochard, Tigran Galstian, Conrad CloutierThe increasing use of specific wavelengths involving light-emitting diodes (LEDs) under greenhouses enables to overcome the lack of light during winter months, helping crops photosynthesis or vegetative growth. However, modification of the light environment as well as the photoperiod may also alter directly or indirectly the activity of both beneficial and pest insects that depend on plants. Here, we submitted the parasitic wasp Aphidius ervi and its main host the pea aphid, to 4 ratios of red(R): blue(B) LEDs used to lengthen the photoperiod inside a growth chamber. We recorded the parasitism rate of aphids and the sex ratio of newly emerged wasps to evaluate if A. ervi could remain an efficient biological control agent under modified light environments. We found that increasing the 8 h of photophase to 16 h by supplementing with R/B LEDs increased the daily parasitic activity of the wasp as well as their egg laying behavior. Under the 100R light supplement, about 80% of the emerged adults were males, against 50% under 25R:75B light treatment. These results indicate that A. ervi remains a good biological control agent when the light environment is modified. However, the use of red light to extend the photophase has the potential to negatively affect population dynamics of these parasitoids due to its male-bias impact on the sex ratio.Graphical abstractGraphical abstract for this article
  • Laboratory tests to estimate the non-target impacts of four Aphidius spp.
           parasitoids in the field
    • Abstract: Publication date: June 2019Source: Biological Control, Volume 133Author(s): Quentin Paynter, David TeulonA ‘risk score’ approach to help determine the potential impact of biological control agents on non-target species, previously proposed for weed biocontrol agents, was examined in an ex post study for insect biocontrol agents. ‘Risk scores’ (% parasitism for non-target aphid species/% parasitism for target aphid species) were calculated for 19 aphid (New Zealand adventive and indigenous) species and 4 introduced (New Zealand) Aphidius biocontrol species, based on previously published choice and no-choice host range laboratory testing. Field hosts for each Aphidius parasitoid and aphid host combination were also examined through an extensive literature review. Strong correlations between ‘risk scores’ for both choice and no-choice laboratory assays and field host binary values (host: yes or no) were obtained for each Aphidius/aphid dataset, but there was no threshold score that indicated using the approach to predict parasitoid field host ranges could result in type II errors. In contrast, a second analysis that categorized aphid hosts as ‘major field hosts’, if literature records indicated high (≥15%) levels of parasitism in the field, showed a clear threshold risk score predicting whether an aphid was a major field host in no-choice tests. We conclude that this approach could potentially be used to predict the likelihood of the impact of Aphidius biocontrol agents on non-target aphid species. We discuss the pros and cons of this approach to help scientists and regulators in the assessment for new biocontrol agent introductions, including the need for this ‘risk score’ approach to be tested on a greater range of insects.Graphical abstractGraphical abstract for this article
  • The efficacy of three seed-destroying Melanterius weevil species
           (Curculionidae) as biological control agents of invasive Australian Acacia
           trees (Fabaceae) in South Africa
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Fiona A.C. Impson, John H. HoffmannAbstractSince the mid-1980s, five species of seed-destroying Melanterius weevils have been used in South Africa as biological control agents against invasive Australian Acacia trees. Recorded levels of seed-destruction by the weevils are highly variable. To gain an understanding of these relationships, four years of observations on three chosen Melanterius/Acacia associations are reported that provide measures of: seed production; larval and pupal survival; adult weevil emergence-patterns and longevity; and levels of seed-destruction. Annual and geographical fluctuations in seed-set are exaggerated by the actions of other competing biological control agents which prevent seeding by destroying buds and flowers. Highly unreliable seed sources, coupled with low levels of larval and pupal survival, probably explain why the weevils are not more prolific. Most adult weevils emerge within six months of their prepupae settling in the soil, but a proportion of the population remains dormant and emerges as adults only in subsequent years. Our data indicates that some adults live for more than a year after emergence and therefore have access to seeds for two or more seasons. These characteristics enable the weevils to persist through years of low seed production and cause higher levels of seed damage in subsequent years than would otherwise be possible. Acacia-seed destruction by the weevils cannot cause measurable declines in the densities or distributions of mature populations of the target plants and thus the weevils could be assessed as unsuccessful biological control agents. However, Melanterius weevils are well adapted and efficient ‘back-up’ agents whose impacts accrue over time and reduce the reproductive fitness of the invasive Australian acacias.
  • Effects of bean seed treatment by the entomopathogenic fungi Metarhizium
           robertsii and Beauveria bassiana on plant growth, spider mite populations
           and behavior of predatory mites
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Fernanda Canassa, Susanna Tall, Rafael A. Moral, Idemauro A.R. de Lara, Italo Delalibera, Nicolai V. MeylingAbstractThe fungal genera Metarhizium and Beauveria are considered as both entomopathogens and endophytes; they are able to colonize a wide variety of plants and can cause increased plant growth and protect plants against pests. In view of the need for new biological methods for plant protection and how promising and little studied candidates entomopathogens are, the aim of this research was to evaluate the potential of two isolates of Metarhizium robertsii (ESALQ 1622) and Beauveria bassiana (ESALQ 3375) to suppress spider mite Tetranychus urticae population growth and ability to promote growth of bean plants Phaseolus vulgaris after seed treatment, in order to develop an innovative strategy by using these fungi as inoculants to improve both spider mites control and plant growth and yield. In addition, behavioral responses and predation rates of the predatory mite Phytoseiulus persimilis towards fungal treated plants and spider mites from these plants were also evaluated in leaf disc assays to assess potential conflicting effects of the fungal inoculations on overall pest control at higher trophic levels. Seed inoculations by the two isolates of M. robertsii and B. bassiana were done individually and in combinations to evaluate potential benefits of co-inoculants. The results showed a significant reduction in T. urticae populations and improved plant development when inoculated with M. robertsii and B. bassiana individually and in combination. The predatory mite P. persimilis showed no difference in the predation rate on T. urticae from treated and untreated plants even though the predators were most likely to feed on spider mites from fungal treated plants during the first half of the trial, and on spider mites from control plants during the remainder of the trial. Overall, the two fungal isolates have potential as seed inoculants to suppress spider mites in bean and the strategy appears to have no conflict with use of predatory mites. Co-inoculation of both fungal isolates showed no additional benefits compared to single isolate applications under the given test conditions.
  • Field evidence and grower perceptions on the roles of an omnivore,
           European earwig, in apple orchards
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Robert J. Orpet, Jessica R. Goldberger, David W. Crowder, Vincent P. JonesAbstractIn agroecosystems, omnivores can be beneficial predators or harmful herbivores. In apple orchards, the omnivorous European earwig (Forficula auricularia) is thought to be a key predator of woolly apple aphid (Eriosoma lanigerum), but has also been implicated in feeding on apple fruit. Assessing the effects of earwigs in orchards is difficult because they are nocturnal, and their damage to fruits can resemble other wounds. Apple orchardists thus may manage earwigs as either predators or pests based on subjective opinions. To understand current opinions on earwigs in apple orchards, we interviewed 15 apple pest management decision-makers in Washington State, USA. To compare opinions to objective measurements, we manipulated earwig abundance within plots at four orchards and collected data on fruit damage, woolly apple aphid abundance, and molecular gut contents of earwigs. Most interviewees thought earwigs were aphid predators, but some thought earwigs could be minor pests, and most were more uncertain about earwigs’ effects relative to other aphid natural enemies. In the field, earwig abundance was negatively correlated to woolly apple aphid abundance, and earwig guts regularly contained woolly apple aphid DNA, even when aphid densities were low. We found no evidence earwigs damaged fruits. Overall, our results suggest earwigs improved biological control and were not pests, so discontinuing the occasional use of insecticides against earwigs could benefit apple growers. More generally, omnivores and difficult-to-observe natural enemies could often have important underappreciated benefits in agriculture.
  • Modelling the distribution of forest pest natural enemies across invaded
           areas: Towards understanding the influence of climate on parasitoid
           establishment success
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): D. Fischbein, M.V. Lantschner, J.C. CorleyAbstractClassical biological control is a pest management practice frequently deployed against invasive insects. However, introduced natural enemies too often fail to establish, and this has been partly explained by climatic mismatching. We evaluate climate matching (using MaxEnt) for three parasitoids, Megarhyssa nortoni, Ibalia leucospoides and Rhyssa persuasoria, released in classical biological control programmes of the pine pest Sirex noctilio in the Southern Hemisphere and explore how climatic factors can influence parasitoid establishment success. Model predictions are compared against data on historical releases in this region. The main results show that for I. leucospoides and M. nortoni the eco-climatic distribution model successfully predicted the establishment in all the regions where the species are currently present. Additionally, for M. nortoni, the model also correctly predicted the regions where the species was released and failed to establish, as is the case of the south of Brazil and the Western Cape, South Africa. However, R. persuasoria established only in some of the regions where the model predicted its presence. These results highlight the usefulness of climatic matching techniques as an effective way to prioritize suitable areas to release specific biological control agents. However, climatic matching modelling does not always guarantee establishment, and likely, several other factors explain failures in establishing populations after releases. Further understanding of the factors affecting success in biological control programs of forest insects at a broad spatial scale may contribute to improve pest management skills of new and established populations of non-native forest insects.
  • Interactive effects of temperature and time on cold tolerance and spring
           predation in overwintering soil predatory mites (Gaeolaelaps aculeifer
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Kim Jensen, Jesper G. Sørensen, Martin HolmstrupAbstractSoil living mites have large potential as biocontrol agents against soil-dwelling pests, but little is known about their ecological and ecophysiological responses to cold. We investigated the interactive effects of acclimation temperature and time on cold tolerance in the laelapid mite Gaeolaelaps aculeifer Canestrini after exposure to 5, 10, 15, or 20 °C for 1, 4, or 8 days. Another group of mites were subjected to simulated winter by gradually lowering the temperature from 20 to 0.8 °C during three months, while measuring tolerance to −2 and −5 °C as well as supercooling point and melt onset temperature of body fluids at start (20 °C; “summer”), at 5 °C (“autumn”), and at 0.8 °C (“winter”). A third group was kept at constant 10 °C as a constant mild cold comparison. We found a strong interaction between exposure temperature and time on cold tolerance, with rapid cold hardening after 24 h at 5 °C but increasing cold acclimation at 10 °C. During simulated winter, tolerance to −2 °C was high after two months at 4.1 °C, but then decreased to intermediate levels after another month at 0.8 °C. The supercooling point did not change over the simulated winter, but melt onset temperature was lowered after 0.8 °C exposure. Mites preyed and reproduced readily following simulated winter, but at lower rates than if kept at constant 10 °C. Our study indicates that G. aculeifer can overwinter following release, and suggests that cold storage is advantageous before inoculative release in early spring.
  • The potential of Brassicaceae biofumigant crops to manage Pleiochaeta
           setosa in sustainable lupin cultivation
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Kevin Dewitte, Sofie Landschoot, Jasper Carrette, Kris Audenaert, Veerle Derycke, Joos Latré, Pieter Vermeir, Geert HaesaertAbstractLupin is prone to infection by Pleiochaeta setosa (Kirchn.) Hughes causing brown spot and root rot in Lupinus species. The control of these diseases is crucial to limit yield losses, but an increased public awareness and European legislative restrictions have resulted in a drastic reduction of allowed pesticides and many research groups invest in alternative biocontrol strategies. In the current study, the inhibitory effect of volatiles, released by two members of the Brassicaceae family (white mustard (Sinapis alba) and fodder radish (Raphanus sativus)), on brown spot and root rot in Lupinus species was evaluated in vitro and in vivo. The in vitro trial showed that root tissue of Brassicaceae was more effective in reducing the vegetative growth of Pleiochaeta setosa than leaf and stem tissues. Furthermore, R. sativus was more effective than S. alba. The GC–MS analysis revealed that dimethyl disulfide and dimethyl trisulfide were predominantly emitted by the tissues of both Brassicaceae. Additionally, the ground root tissue of R. sativus emitted 4-isothiocyanato-1-(methylthio)-1-butene, whereas the stem + leaf tissue emitted benzyl isothiocyanate. Benzyl isothiocyanate was also released by the ground S. alba root tissue, whereas the leaf + stem tissue emitted 3-butenyl isothiocyanate. In vitro trials with pure dimethyl disulfide and dimethyl trisulfide confirmed the antifungal effect of the volatiles released by these sulfides. For dimethyl disulfide 7.95 mg per Petri dish was necessary to (almost) completely inhibit mycelium growth, whereas for dimethyl trisulfide 1.20 mg per Petri dish was sufficient to prevent fungal growth. In addition, a trial with allyl isothiocyanate showed that for this compound even lower doses (0.50 mg per Petri dish) stopped the growth of the fungus. The results obtained with the pot trial illustrated that the amendment of Brassicaceae species significantly reduced the P. setosa infection level. Also in the field, incorporation of Brassicaceae species suppressed P. setosa. From this study, it can be concluded that Brassicaceae species are a powerful tool to manage P. setosa in lupin cultivation. However, it should be combined with other control practices since the amendment of these biofumigant crops could not completely inhibit symptom development.
  • Field assessment of microbial inoculants to control Rhizoctonia root rot
           on wheat
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Stephen J. Barnett, Ross A. Ballard, Christopher M.M. FrancoRhizoctonia root rot caused by Rhizoctonia solani AG8 is a major disease in dryland cereal crops. Previous research identified a suite of microbes using in planta bioassay screening that are effective as seed-coated inoculants for control of Rhizoctonia root rot on wheat. This paper assessed 23 strains in fields in Australia with a history of naturally occurring R. solani AG8. Due to the patchy nature of Rhizoctonia root rot in the field, a 2-phase split-plot field trial system was used to allow comparison for disease control efficacy in the same disease space. Seed applied strains were first assessed for their ability to reduce Rhizoctonia using ‘microplots’ which compare adjacent treated and untreated one metre rows. Up to 10% increases in plant growth and a 32% reduction in root disease was measured at eight weeks after sowing. Selected strains were then assessed in 20 m six row (3 + 3) split plots for their effects on early season wheat growth and root damage and for grain yield. A Paenibacillus and a Streptomyces strain were identified which were able to reduce root damage by 20% and 32% and increase grain yield by 4.2% and 2.8%, respectively, compared to untreated controls. The current best registered chemical control for Rhizoctonia root rot reduced root disease by 35% and increased yield by 3.0% in the same trial.Graphical abstractGraphical abstract for this article
  • Potential distribution of Bactrocera oleae and the parasitoids Fopius
           arisanus and Psyttalia concolor, aiming at classical biological control
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Fernanda Appel Müller, Naymã Pinto Dias, Marco Silva Gottschalk, Flávio Roberto Mello Garcia, Dori Edson NavaAbstractBactrocera oleae (Rossi, 1790) (Diptera: Tephritidae) is monophagous and one of the primary plagues of the olive tree (Olea europaea L. (Lamiales: Oleaceae)), causing economic losses worldwide. The pest has been detected in the United States and Mexico, showing potential to invade new areas. Among the parasitoids used to control B. oleae, Fopius arisanus (Sonan, 1932) and Psyttalia concolor (Szépligeti, 1910) (Hymenoptera: Braconidae) are considered cenobiont and sinovigene endoparasitoids. Through the study of the potential geographic distributions, the size of regions environmentally suitable for the species can be understood, and the areas of distribution of the pest can be related with those of the parasitoids, with the goal to estimate whether the parasitoids would be suitable for use in classic biological control. The aim of this study was to map the potential global distribution regions, with an emphasis on South America, of B. oleae and the two parasitoids F. arisanus and P. concolor and show the overlap of geographically environmentally adequate areas for the joint establishment of the pest and natural enemy. For map the potential global distribution regions, a predictive model correlative of the distribution of the species was used, generated from known data of the localities of occurrence of insects and environmental predictor variables. The algorithm chosen for the modeling was Max Entropy (MaxEnt). The evaluation of the model was based on the mean Area Under the Curve (AUC), which was 0.966, 0.982 and 0.995 for B. oleae, F. arisanus, and P. concolor, respectively, indicating good predictive performance of the models and reliable projections. In general, the most significant extent of the potential distribution of F. arisanus was observed in Asia (most likely because it is the region of origin), Central America and South America. In Africa and North America, F. arisanus was also the most comprehensively distributed, in general; however, in the regions related to the occurrence of B. oleae and olive cultivation, P. concolor presented a greater potential distribution than that of F. arisanus. In Europe and Oceania, P. concolor had potential distribution projected in areas with olive groves.
  • Bacillus subtilis TE3: A promising biological control agent against
           Bipolaris sorokiniana, the causal agent of spot blotch in wheat (Triticum
           turgidum L. subsp. durum)
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Eber Villa-Rodríguez, Fannie Parra-Cota, Ernestina Castro-Longoria, Jaime López-Cervantes, Sergio de los Santos-VillalobosBipolaris sorokiniana, the causal agent of wheat spot blotch, is an emerging phytopathogen in the Yaqui Valley, Sonora, Mexico. Currently, the unique method to control spot blotch on that region is employing synthetic fungicides with environmental and human health issues. Thus, the aim of this work was to identify and characterize native wheat-associated bacteria in order to find promising biological control strains that can be used as a sustainable alternative to control spot blotch. The identification of antagonistic strains was carried out by confrontation assay against B. sorokiniana. Antagonistic strains to B. sorokiniana were taxonomically classified by 16S rRNA gene sequencing, and characterized on important biological traits: (i) inhibition of the target phytopathogen, (ii) growth rate, and (iii) cytotoxic activity. Out 195 bacterial strains tested, 14 exhibited antagonistic activity against B. sorokiniana at different degree (1.6–8.0 mm of inhibition zone). The Antagonistic strains were taxonomically identified as members of Bacillus (eight strains), Paenibacillus (one strain), Pseudomonas (two strains), Achromobacter (one strain), Delftia (one strain), and Stenotrophomonas (one strain). The strain TE3, identified as Bacillus subtilis, showed promising biological control traits: (i) broad spectrum inhibition against B. sorokiniana, (ii) growth capacity in synthetic minimal medium, and (iii) non-cytotoxic activity to erythrocyte (γ-hemolysis). The application of cell suspension or cell-free culture filtrate of B. subtilis TE3 under highly conducive conditions (28 °C and 100% HR) for wheat spot blotch, resulted in a significant reduction of that disease. In conclusion, B. subtilis TE3 and its antifungal metabolites are promising effective treatment to control the causal agent of the wheat spot blotch.Graphical abstractGraphical abstract for this article
  • Free living nematodes as alternative prey for soil predatory mites: An
           interdisciplinary case study of conservation biological control
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): L.H. Azevedo, L.G. Leite, J.G. Chacon-Orozco, M.F.P. Moreira, M.P. Ferreira, L.M. González-Cano, V. Borges, D. Rueda-Ramírez, G.J de Moraes, E. PalevskySpecies of soil predatory mites feed on a diverse diet making them excellent biocontrol candidates for conservation biocontrol programs. Free-living nematodes (FLN) are commonly found in soils and serve as prey for many soil predatory mites, but as far as we know, have never been used as alternative prey to enhance the efficacy of soil predatory mites for conservation biological control. Our goal in this case study was to determine whether the FLN Rhabditella axei, provisioned as complementary prey, would improve the efficacy of Macrocheles embersoni as a biocontrol agent of the housefly Musca domestica. Two experimental setups differing temporally and spatially were conducted. The first, performed in small Petri dish arenas over 10 days, assessed M. embersoni fecundity and predation of L1 M. domestica, with or without supplementation of R. axei. The second, carried out in plastic containers over four weeks, was provisioned three times a week with M. domestica eggs and fresh larva diet, with or without nematode supplementation. The efficacy of fly immature predation was estimated by counting the adult flies that emerged. In the short-term, small arena, experiment, nematode supplementation reduced predation. Similarly, in the long-term experiment in plastic containers, more flies emerged in the nematode supplemented treatment during the 3rd week (the 1st week of fly emergence). However, in the 4th week, fly emergence dropped dramatically in the nematode supplemented treatment, whereas fly emergence continued to escalate in the treatment that received only fly eggs, and M. embersoni abundance was about a third of that in the nematode supplemented treatment. In summary, complementing the diet of M. embersoni with nematodes resulted in higher predator abundance and better biological control.Graphical abstractGraphical abstract for this article
  • Feeding strategy and prey selectivity in Cnesterodon decemmaculatus and
           Jenynsia multidentata in experimental enclosures: Importance for the
           biological control of mosquito populations
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Alejo Fabian Bonifacio, Virginia Lara Usseglio, Andrea Cecilia Hued, Ma. Liliana Aun, Ricardo Armando MartoriMosquitoes pose a threat to human and animal health due they act as vectors for numerous pathogens and parasites which cause disease. Several methods are used to control mosquito populations. Chemical pesticides can be harmful to human health and others lifeforms, including natural predators, and mosquitoes have been well documented to develop resistance through time. Alternative methods for mosquito control must be explored, being the biological control an effective and environmentally friendly strategy; when this is carried out with native species that are not exported out of their natural limits. The most widely used biocontrol agents of mosquito populations are the fishes of the genus Gambusia spp., nevertheless, these species have become invasive species in several places where they have introduced affecting non-target species. Widespread native fish species could be an appropriate alternative to these invasive species and circumvent their negative impacts. C. decemmaculatus and J. multidentata are widely distributed native fish of temperate zones of South America. The main goal of our work was analyze the feeding strategy and prey selectivity in Cnesterodon decemmaculatus and Jenynsia multidentata focusing on mosquito biocontrol implications. The feeding strategy observed for both C. decemmaculatus and J. multidentata showed that the items that had the highest percent of prey-specific abundance were the mosquito larvae. The selectivity index displayed by C. decemmaculatus and J. multidentata suggested a significant selection for mosquito larvae and a significant avoidance of copepods. In this work, the active selection of C. decemmaculatus and J. multidentata for mosquito larvae was determined, allowing us to propose and support their use as useful species for the biological control of mosquitoes.Graphical abstractGraphical abstract for this article
  • Elusive enemies: Consumptive and ovipositional effects on mosquitoes by
           predatory midge larvae are enhanced in dyed environments
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Ross N. Cuthbert, Natali Ortiz-Perea, Jaimie T.A. Dick, Amanda CallaghanAbstractMosquito-borne disease incidences continue to proliferate and cause enormous mortality and debilitation rates. Predatory natural enemies can be effective in population management strategies targeting medically-important mosquito species. However, context-dependencies and target organism behavioural responses can impede or facilitate biological control agents. Black pond dye has been shown to be a strong mosquito oviposition attractant, and could potentially be used alongside predatory agents to create mosquito population sink effects. Here, we thus examine the predatory impact of larvae of the non-biting chaoborid midge Chaoborus flavicans towards larvae of the West Nile virus vector mosquito complex Culex pipiens in the presence and absence of black pond dye. We then examine the ovipositional responses of C. pipiens to predation risk and dye in laboratory-, semi-field- and field-based trials. Larval C. flavicans exhibited potentially population destabilising type II functional responses towards mosquito larvae irrespective of the presence of pond dye. Neither consumption rates nor functional response parameters (attack rates, handling times) were significantly influenced by the presence of dye, indicating a use of hydromechanics to detect mosquito prey by chaoborids. Wild-caught adult C. pipiens did not avoid predatory chaoborids when ovipositing, however they were significantly more attracted to oviposit in dye-treated water regardless of the presence of predators. We thus demonstrate high predatory impact towards mosquito larvae by non-biting chaoborid midges during their predaceous aquatic larval stages, and proliferations of such predators may assist or augment control efforts for mosquitoes. Our results suggest a lack of influence of predatory dipterans on oviposition selectivity by C. pipiens mosquitoes, and that pond dye may enhance the efficacy of select predatory biological control agents through the creation of population sinks, characterised by high rates of oviposition and subsequent predation.
  • Modeling interactions and dynamics of Aphidius matricariae and Praon
           volucre (Hymenoptera: Braconidae) on two major aphid species in a
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Zahra Tazerouni, Ali Asghar Talebi, Yaghoub Fathipour, Mahmoud Soufbaf, Gadi V.P. ReddyInterspecific interactions between parasitoid wasps affect the selection of effective biological control agents. In this study, we investigated the effects of extrinsic interspecific interactions between Aphidius matricariae Halifay and Praon volucre (Haliday) (Hymenoptera: Braconidae) on the population sizes of each parasitoid on Myzus persicae (Sulzer) on sweet pepper and Aphis gossypii Glover on cucumber, at 25 ± 2 °C, 60 ± 5% RH and a 14:10 h L:D photoperiod. The population dynamics of these parasitoids were also analyzed numerically using the Lotka–Volterra competition model. Interspecific interaction between the two parasitoids had reduced the population size of each parasitoid on both host aphids. The effect of this interspecific interaction b was more pronounced for P. volucre. Without interspecific interactions, the mean population size of P. volucre varied from 85.2 ± 10.70 to 107.1 ± 12.40 numbers on M. persicae and from 187.8 ± 18.4 to 249.8 ± 24.7 numbers on A. gossypii. Under conditions of coexistence with A. matricariae, however, the abundance of P. volucre significantly decreased to 8.92 ± 2.65–17 ± 5.16 numbers on M. persicae and 53.6 ± 19–65.3 ± 25.2 numbers on A. gossypii. Phase diagrams and time trajectories showed that coexistence of these two parasitoids on M. persicae and A. gossypii lasted for just a short period after which the inferior parasitoid population, P. volucre, declined to zero.Graphical abstractGraphical abstract for this article
  • Use of biocontrol agents as potential tools in the management of chestnut
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Sergio Murolo, Jonathan Concas, Gianfranco RomanazziCastanea sativa is a widespread and important multi-purpose tree in the Mediterranean area. Recently, intensive infestation of gall wasp decreased the production of chestnut, and makes the plants more susceptible to Cryphonectria parasitica, the causal agent of chestnut blight. Generally, biological control of chestnut blight is through natural spread or artificial release of hypovirulent strains of C. parasitica. However, this approach is not always successful. The aim here was to evaluate alternative approaches for control chestnut blight based on application of antagonistic microorganisms. In-vitro antagonistic activities of fungal species Trichoderma and Penicillium were tested after in vitro isolation from chestnut bark. In dual cultures, these antagonistic fungi consistently reduced growth of C. parasitica. Three commercial formulations based on Trichoderma spp., Glomus spp. and Bacillus subtilis were tested at three doses, both in vitro and directly applied to cuttings of chestnut stems as co-inoculations and as separated inoculations with C. parasitica mycelium plugs. With co-inoculation, B. subtilis showed the best performance against chestnut blight, with necrotic areas reduced by>70%. In separated inoculations, B. subtilis reduced the size of cankers on chestnut stems, by 29%–67%, as also for Trichoderma spp., by 36%–65%, and Glomus spp., by 31%–63%. Application of commercial formulations based on antagonistic microorganisms are effective tools in management of chestnut blight.Graphical abstractGraphical abstract for this article
  • Frequency of resistance alleles to Lysinibacillus sphaericus in a Culex
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Eloína Maria de Mendonça Santos, Karlos Diogo de Melo Chalegre, Alessandra Lima de Albuquerque, Lêda Regis, Cláudia Maria Fontes de Oliveira, Maria Helena Neves Lobo Silva-FilhaCulex quinquefasciatus resistance to the Binary protoxin from Lysinibacillus sphaericus biolarvicides can rely on mutations in the cqm1 gene, which encodes its Cqm1 receptor. Bacillus thuringiensis svar. israelensis (Bti) biolarvicides can be used to manage L. sphaericus resistance since their protoxins act through distinct receptors from Cqm1. This study aimed to evaluate the effect of a L. sphaericus/Bti combined biolarvicide treatment on the frequency of three cqm1 resistance alleles in Cx. quinquefasciatus larvae from one subarea (SA2) compared to another (SA1) where only L. sphaericus was kept. Larvae collected before and during a two-year trial were subjected to bioassays and PCR assays. Susceptibility to L. sphaericus showed oscillations in both areas, but no significant alterations of the lethal concentrations were detected. The pre-trial frequency of the resistance alleles was 0.057, while during the trial, the mean frequency was significantly lower in SA2 (0.068) than in SA1 (0.088). All three alleles investigated were detected in the study subareas and the cqm1REC-D19 was the most frequent allele found, regardless the treatment employed. This study showed that the use of the L. sphaericus/Bti biolarvicide was associated with a lower frequency of the resistance alleles and can be a useful tool to prevent the onset of L. sphaericus resistance.Graphical abstractGraphical abstract for this article
  • Small-scale dispersal of a biological control agent – Implications
           for more effective releases
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Ashley B.C. Goode, Carey R. Minteer, Philip W. Tipping, Brittany K. Knowles, Ryann J. Valmonte, Jeremiah R. Foley, Lyn A. GettysAbstractEichhornia crassipes (Martius) Solms Laubach (Liliales: Pontederiaceae) was introduced to Florida in the 1880s as an ornamental and it once infested thousands of square kilometers across the state. Megamelus scutellaris Berg (Hemiptera: Delphacidae) was developed as a classical biological control agent for this plant primarily because its free-living life stages allow it to better integrate with herbicides, which are currently used as the main control method for E. crassipes in Florida. Mass rearing and distribution programs can accelerate the benefits of biological control by augmenting natural dispersal, but an optimal release strategy must consider the entire system including the agent, the target weed, and the habitat. The effectiveness of various release strategies was evaluated using a tank experiment where single and multiple releases of either adult M. scutellaris only or E. crassipes infested with M. scutellaris eggs were compared to control treatments. The post-release dispersal capability of brachypterous M. scutellaris was evaluated using a linear transect of E. crassipes. Two density release treatments were tested and emerging nymphs were used as a proxy for female dispersal distances. All release treatments resulted in successful M. scutellaris population establishment and levels of M. scutellaris were not significantly different among them. The dispersal experiment indicated that adult females oviposit near the release point before dispersing. While the release experiment indicated that all treatments were similar, the continually fluctuating populations of E. crassipes makes establishment of populations difficult in the field. By releasing both adults and infested plants, additional propagule pressure can be attained from a single release event which can counter the tendency of adult M. scutellaris to disperse rapidly following release.
  • Spatial and seasonal distribution of egg parasitoids of the sharpshooter
           Tapajosa rubromarginata (Hemiptera: Cicadellidae: Proconiini) on feral
           Johnson grass and commercial citrus host in Argentina
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Eduardo G. Virla, Guido A. Van Nieuwenhove, Florencia Palottini, Serguei V. Triapitsyn, Guillermo A. LogarzoHymenopterous egg parasitoids are considered promising biocontrol agents against insect vectors of the bacterium Xylella fastidiosa Wells. We studied the spatial and seasonal occurrence of the egg parasitoid guild of the sharpshooter Tapajosa rubromarginata (Signoret) (Hemiptera: Cicadellidae: Proconiini), a known vector of X. fastidiosa, in a commercial lemon orchard in Tucumán Province, Argentina. Egg masses of T. rubromarginata laid at three different heights were examined for two years, in spring and in summer, in order to determine the specific composition and abundance of its parasitoids. The overall rate of egg parasitoid emergence was about 54%. Fourteen species of parasitoids were obtained from egg masses of this host, nine belonging to the genus Cosmocomoidea Howard (Mymaridae) and the rest to five genera of Trichogrammatidae. The percentage of emerged wasps was higher in citrus than in the lower grassy stratum and it was similar in both seasons. Mymarids were generally more frequent and abundant than trichogrammatids, dominating as egg parasitoids of T. rubromarginata on citrus leaves, whereas trichogrammatids were more frequently found parasitizing egg masses of the same host on Johnson grass leaves. Three species were predominant among all the parasitoids, the trichogrammatid Zagella delicata De Santis and the mymarids Cosmocomoidea annulicornis (Ogloblin) and C. metanotalis (Ogloblin), accounting for about three-quarters of the emerged wasps; the other parasitoid species were occasionally or rarely found in the orchard.Graphical abstractGraphical abstract for this article
  • A biofertilizer with diazotrophic bacteria and a filamentous fungus
           increases Pinus pinaster tolerance to the pinewood nematode
           (Bursaphelenchus xylophilus)
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): M. Nunes da Silva, M.E. Pintado, B. Sarmento, N.P. Stamford, M.W. VasconcelosThe pine wilt disease (PWD), caused by the pine wood nematode (PWN) Bursaphelenchus xylophilus, is a devastating illness that mainly affects P. pinaster trees, and that poses great environmental and economic challenges. Current disease management involves the cut down of infected trees, tree fumigation, use of nematicides, or the control of the insect vector; however, these methodologies are expensive, labour-intensive and have limited success. The aim of this work was to evaluate the effect of a biofertilizer enriched with diazotrophic bacteria and a chitosan-producing fungus, Cunninghamella elegans, in inducing P. pinaster and P. pinea resistance against the PWN. In non-inoculated (control) P. pinaster plants, PWN population significantly increased (ca. 2.3-fold) throughout the experimental period, whereas in plants treated with 7.5 and 15% of biofertilizer nematode numbers were up to 36.3-fold lower than in control plants. In P. pinea, nematode numbers decreased with time for all biofertilizer concentrations tested, and P. pinea had up to 27.3-fold lower nematode counts than P. pinaster. In addition, the biofertilizer prevented the decrease of photosynthetic pigments and the reduction of water content in infected P. pinaster plants. In P. pinea the biosynthesis of phenolics increased in PWN-inoculated plants, especially in the presence of the biofertilizer. The addition of this biofertilizer to soils forested by P. pinaster may improve plant defence and could be a potentially simple and inexpensive strategy for the control of the PWD.Graphical abstractGraphical abstract for this article
  • Biocontrol activities of metal-tolerant endophytes against Ganoderma
           boninense in oil palm seedlings cultivated under metal stress
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Carrie Siew Fang Sim, Yuen Lin Cheow, Si Ling Ng, Adeline Su Yien TingTwo metal-tolerant endophytes (Diaporthe miriciae LF9 and Trichoderma asperellum LF11) were studied in vitro for antifungal activities using dual culture assay. Both isolates inhibited Ganoderma boninense (GB) under metal and non-metal stress, with higher inhibition by T. asperellum LF11 than D. miriciae LF9. T. asperellum LF11 was unaffected by the metals, consistently inhibiting GB (100%) in both conditions. In contrast, inhibitory activities by D. miriciae LF9 was encouraged under metal (32.81–70.64%) compared to non-metal (14.07%) stress; higher in Cu2+ (70.64%) and Zn2+ (63.10%) than Pb2+ (51.79%) and Cd2+ (32.81%). These in vitro activities differed from in vivo findings. After 12 weeks, infected seedlings of oil palms inoculated with D. miriciae LF9 showed lower disease incidence (DI) in non-metal (33%) and multi-metal (67%) treated soils, thus suggesting enhanced tolerance of seedlings towards infection. Treatment with D. miriciae LF9 also delayed the onset of symptoms in the seedlings. Disease severity (DS) was lower for seedlings in non-metal (11%) and multi-metal (22%) treated soils, suggesting D. miriciae LF9 slowed the disease development. On the contrary, T. asperellum LF11 was less effective. Seedlings did not show improved tolerance under non-metal (67%) and multi-metal (100%) stress conditions. The isolate was also less successful in slowing disease development with DS of 33% and 56% observed in seedlings in non-metal and multi-metal treated soils, respectively. The lower endophytic inhibition towards GB in multi-metal treated soils was possibility attributed to higher metal toxicities by the several metals present, thus portraying complex interactions among metals, endophytes and seedlings. Nevertheless, the endophytes suppressed GB in both conditions, hence can be further studied for enhanced performance in metal-laden soils.Graphical abstractGraphical abstract for this article
  • The global diversity of Deladenus siricidicola in native and
           non-native populations
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Katrin N.E. Fitza, Jeff R. Garnas, Maria J. Lombardero, Matthew P. Ayres, Flora E. Krivak-Tetley, Rodrigo Ahumada, Brett P. Hurley, Michael J. Wingfield, Bernard SlippersAbstractThe nematode Deladenus siricidicola is the primary biological control agent of Sirex noctilio, a globally invading woodwasp pest of Pinus species. Preliminary studies on the diversity of populations of D. siricidicola revealed very low diversity in the Southern Hemisphere where they have been introduced for the purpose of biological control. The potential to augment biocontrol efficacy by increasing genetic diversity in biocontrol programs motivated this study, which investigated the patterns of genetic diversity in D. siricidicola across eight countries, including the presumed native range (Spain), areas of accidental introduction (Canada and the USA) and countries D. siricidicola has been intentionally released (Argentina, Brazil, Chile, New Zealand and South Africa). Nematodes were screened using mitochondrial COI sequence data and twelve microsatellite markers. Analyses of these data identified three distinct lineages from North America (Lineage A), the Southern Hemisphere (Lineage B) and Spain (Lineage C). Strains from Chile were an exception as they appear to represent an admixture of lineages A and B. This suggests a common origin of populations throughout the Southern Hemisphere, with a second introduction from North America into Chile. The introduction into North America is distinct from that in the Southern Hemisphere and probably originated from Europe. It is evident that substantial genetic diversity exists in D. siricidicola globally, which could be exploited to augment the reduced diversity in some populations used in biocontrol programs.
  • Life history traits of the coccinellids Scymnus subvillosus and S.
           interruptus on their prey Aphis spiraecola and A. gossypii: Implications
           for biological control of aphids in clementine citrus
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): J.P.R. Bouvet, A. Urbaneja, C. MonzoPredator-prey interactions are not static, but spatially and temporally dynamic. In addition to the climatic conditions and the prey density, the dynamics of predator populations may be influenced by the suitability of their diet. Therefore, to better understand aphid predator-prey relationships within food webs, it is necessary to know how their life history traits are affected by diet quality. In this research, under laboratory conditions, the suitability of the two most abundant aphid species in citrus agroecosystems of the Western Mediterranean basin, Aphis gossypii and A. spiraecola were evaluated for two of their principle natural enemies, the coccinellid predators Scymnus subvillosus and S. interruptus. The intrinsic rate of increase of S. subvillosus was found to be higher than that of S. interruptus regardless of the type of prey consumed. Some biological parameters of S. interruptus were lower when they were exclusively fed A. spiraecola; as opposed to when only fed A. gossypii. These differences were not found with S. subvillosus. When a mixed diet of both aphids was offered, the fitness of both predators was higher than when they were each fed only a single aphid species. These laboratory observations were further confirmed under field conditions, wherein S. subvillosus abundance was greater in those colonies where A. spiraecola was predominant. On the other hand both, S. subvillosus and S. interruptus were found equally in A. gossypii colonies. Implications of these results for the biological control of aphids in this crop are discussed.Graphical abstractGraphical abstract for this article
  • Acaricides compatibility with the armored scale predator Rhyzobius
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Roy Kaspi, Reut Madar, Sylvia DomeradzkiAbstractRhyzobius lophanthae Blaisdell (Coleoptera: Coccinellidae) is an important worldwide predator of armored scale species in citrus orchards. Laboratory bioassays were performed to test the impact of acaricides, commonly used in citrus in general, and sulfur pesticides in particular, on acute mortality of R. lophanthae adults and larvae. The lethal toxicity of six acaricides to R. lophanthae (abamectin, spirodiclofen, fenbutatin oxide, summer oil, and two sulfur formulations) were evaluated. In addition, sulfur formulations were also tested at various rates, as high as 8-fold the recommended label rate. Toxicity was tested in two situations: (i) direct spray applications and (ii) feeding and contact with dry residues on prey items (oleander scales, Aspidiotus nerii). The pesticide abamectin combined with summer oil was highly toxic to R. lophanthae adults and larvae in both direct applications and pesticide residue situations. In contrast, pesticides fenbutatin oxide, spirodiclofen, summer oil, and two sulfur formulations of all doses, were found to be harmless to both R. lophanthae adults and larvae. Our findings suggest that all tested pesticides except for abamectin, are harmless and may be considered compatible with R. lophanthae. Moreover, our data show that R. lophanthae was not affected by high doses of sulfur solutions.
  • Impact of the zoophytophagous predator Engytatus varians (Hemiptera:
           Miridae) on Bactericera cockerelli (Hemiptera: Triozidae) control
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Daniel Alberto Pérez-Aguilar, Ana Mabel Martínez, Elisa Viñuela, José Isaac Figueroa, Benjamín Gómez, Sinue Isabel Morales, Antonio Tapia, Samuel PinedaAbstractEngytatus varians (Distant) (Hemiptera: Miridae), a polyphagous predator that is widely distributed, has recently been documented for the first time in Mexico, feeding on nymphs of the very detrimental pest of several solanaceous crops Bactericera cockerelli (Sulc.) (Hemiptera: Triozidae). The predation of this mirid was evaluated in a greenhouse in 7 m2 cages containing tomato (Solanum lycopersicum Miller) plants for 12 weeks. Two release rates, 1 and 4 adults of E. varians (Ev)/plant, were studied and compared to the control (0 Ev/plant). An 80 to 90% reduction in both nymphs and adults of B. cockerelli occurred when 1 or 4 adults of Ev/plant were released irrespective of the pest life stage. The cumulative number of E. varians nymphs and adults per day was significantly higher in the treatments than in the control (30 and 3, respectively). On the other hand, due to its zoophytophagous habits, E. varians can feed on tomato plants and cause necrotic rings on the leaves; therefore, this type of injury was also recorded. The number of necrotic rings/leaf was inversely proportional to prey presence, but no significant differences were observed between the treatments. Our results point to E. varians being able to establish and control B. cockerelli populations under greenhouse conditions, without causing significant damage to tomato plants. The potential use of this predator as a biological control agent of B. cockerelli is discussed.
  • Trehalose increases the oxidative stress tolerance and biocontrol efficacy
           of Candida oleophila in the microenvironment of pear wounds
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Xiaobao Nie, Changfeng Zhang, Changxing Jiang, Ruichang Zhang, Fengjun Guo, Xinguang FanAbstractHarvested fruit tissues produce reactive oxygen species (ROS) in response to wounding. ROS production is further elevated when biocontrol yeasts are introduced into the wounds, where they act as a bio-elicitor and this results in an environment in which the biocontrol yeast is subject to oxidative stress. In the present study, the effect of trehalose, a non-reducing disaccharide and a major reserve carbohydrate, on the level of oxidative stress tolerance of the biocontrol yeast Candida oleophila was examined in wounded pear fruits. Results indicated that the level of trehalose in C. oleophila yeast cells increased when they were cultured in a trehalose-containing medium. Exposure to a trehalose-medium and the increase in internal trehalose improved the adaptation of C. oleophila to the oxidative environment present in pear fruit wounds. Trehalose-treated cells exhibited a lower accumulation of ROS and mitochondrial impairment compared to untreated, control cells when they were introduced into wounded pear fruit. The trehalose treatment up-regulated the expression of antioxidant genes, including peroxisomal catalase and thioredoxin reductase, in yeast cells. Trehalose-treated yeast also exhibited a faster growth rate in pear wounds and greater biocontrol efficacy against blue mold (Penicillium expansum) and Alternaria rot (Alternaria alternata) than untreated, control yeast. These results support the premise that trehalose improves the biocontrol efficacy of C. oleophila via the activation of antioxidant defense systems which support a faster rate of growth of the yeast in wounds of pear fruit.
  • Innate and learned olfactory attraction to flowering plants by the
           parasitoid Cotesia rubecula (Marshall, 1885) (Hymenoptera: Braconidae):
           Potential impacts on conservation biological control
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Shakira Fataar, Ansgar Kahmen, Henryk LukaAbstractIn conservation biological control, flowers can be used to increase the biological control potential of parasitoids, which benefit from the offered food sources. Besides exhibiting exploitable nectar, flowers should preferably be olfactorily attractive, as highly attractive flowers are easily located, reducing the time spent searching for food and subsequently increasing the per capita host searching efficiency. In this study we thus focused on the olfactory attractiveness of Fagopyrum esculentum Moench (Polygonaceae), Centaurea cyanus L. (Asteraceae) and Vicia sativa L. (Fabaceae) to Cotesia rubecula (Marshall, 1885) (Hymenoptera: Braconidae), a larval parasitoid of the cabbage pest Pieris rapae (Linnaeus, 1758) (Lepidoptera: Pieridae). With a Y-tube olfactometer we found that C. cyanus and to a lesser extent V. sativa successfully attract C. rubecula. Also F. esculentum attracts C. rubecula, but only after a rewarding feeding experience. All three tested flowers seem to be suitable to be exploited in conservation biological control programs to control P. rapae in brassica fields. Even though not every flower offering accessible nectar is also innately attractive, it can still be suitable for conservation biological control purposes as feeding experience can change this attraction. In fact, the application of mixtures containing attractive and rewarding flowers could help increase the success of such programs.
  • Molecular characterization of Hydrellia lagarosiphon, a leaf mining
           biological control agent for Lagarosiphon major, reveals weak variance
           across large geographic areas in South Africa
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): Rosie Mangan, James C. Carolan, Jan-Robert BaarsGraphical abstractGraphical abstract for this article
  • Linking parasitoid nectar feeding and dispersal in conservation biological
    • Abstract: Publication date: May 2019Source: Biological Control, Volume 132Author(s): George E. HeimpelAbstractThe nectar provision hypothesis posits that biological control by parasitoids can be enhanced by providing supplemental nectar in the vicinity of cropland. The rationale for this hypothesis is that parasitoid longevity and fecundity can be greatly enhanced by sugar meals and that many agricultural areas are devoid of naturally occurring sugar sources. While some experimental field studies have produced results supporting the nectar provision hypotheses, many others have failed to show that supplemental nectar can improve biological control by parasitoids. I propose that some parasitoids may engage in medium- or long-range dispersal upon feeding on nectar and thus not contribute to local parasitism adjacent to flower plantings. If true, this could help to explain some of the negative results of nectar supplementation experiments. I further propose that certain conditions favor nectar-induced dispersal and discuss four of these here: (i) the risk of self-superparasitism, (ii) the risk of density-dependent hyperparasitism, (iii) benefits of ‘spreading the risk’ of catastrophic mortality and (iv) the risk of inbreeding among parasitoid offspring.
  • Field Evaluation of Insecticides and Application Timing on Natural Enemies
           of Selected Armored and Soft Scales
    • Abstract: Publication date: Available online 16 March 2019Source: Biological ControlAuthor(s): C.R. Quesada, C.S. SadofScale insects (Hemiptera: Coccoidea) are among the most problematic pests of woody plants in protected culture and urban landscapes. When outbreaks of scale insects occur, insecticides are often applied to reduce host damage. To select reduced risk insecticides that can complement the mortality contributed by natural enemies, the selectivity and residual toxicity of each insecticide must be considered within the context of the seasonal biology of both the pest and its natural enemies. We studied how timing of applying reduced risk insecticides affected the natural enemies of scales in relation to their life histories and seasonal abundance. This study was conducted on trees that were naturally infested with either the soft scale, calico scale Eulecanium cerasorum (Cockerell) or armored scales, striped pine scale Toumeyella pini (King) and pine needle scale Chionaspis pinifoliae (Fitch). Insecticides were applied to target the most susceptible life stages of each scale insect. We found that patterns of the seasonal abundance of natural enemies were synchronized with the life history of each scale insect and took the shape of a rising and falling wave. Overall, impacts of insecticides on parasitoids and predators were influenced by the timing of their applications in relation to when natural enemy abundance began to rise at the cusp of their wave of abundance. Application one month prior to this cusp did not reduce seasonal totals of natural enemy abundance, regardless of insecticide selectivity or residual toxicity. In contrast, when applications were made at the cusp of the natural enemy wave, foliar applications of bifenthrin had greater adverse side effects on natural enemy populations compared to foliar applications of pyriproxifen, spirotetramat, spiromesifin, and chlorantraniliprole or a soil application of dinotefuran. We present evidence to suggest that restricting applications during the cusp of the natural enemy activity wave can result in a better integration of chemical and biological control.Graphical abstractWhen applied one month before detectible natural enemy activity, insecticides did not reduce their total seasonal abundance. In contrast, when applied later in the season at the cusp of the wave of natural enemy activity, insecticide affected their abundance according their selective toxicity. Arrows indicate time of applicationGraphical abstract for this article
  • Marker assisted detection and LC-MS analysis of antimicrobial compounds in
           different Bacillus strains and their antifungal effect on Sclerotinia
    • Abstract: Publication date: Available online 16 March 2019Source: Biological ControlAuthor(s): Ayaz Farzand, Anam Moosa, Muhammad Zubair, Abdur Rashid Khan, Alvina Hanif, Hafiz Abdul Samad Tahir, Xuewen GaoAbstractBacillus strains are well studied for antagonistic effect against fungal pathogens, but the selection of potential antifungal strains is laborious and time-consuming process. Newly developed genetic markers and LC-MS based detection was undertaken simultaneously to detect eight antimicrobial compounds viz., surfactin, bacillomycin, iturin, fengycin/plipastatin, bacilysin, bacillaene, bacillibactin and plantazolicin in forty-seven Bacillus strains. Out of these strains, 19 were positive for the presence of marker genes encoding antimicrobial compounds. Bacillus strains FZB42, EZ1509, EZ1507, VM10, GBAC46, VM49 and LLCG43 possessed genes for maximum number of antimicrobial compounds. LC-MS analysis of antimicrobial compounds showed corresponding results except OKB105 and 168. Contrary to marker-based detection of genes, LC-MS analysis revealed that OKB105 can produce surfactin but unable to synthesize fengycin, while 168 was deficit in both compounds. To assay antifungal potential, 19 Bacillus strains and their methanolic extracts were tested in vitro to inhibit mycelial growth of S. sclerotiorum. Results revealed that EZ1509, VM10, GBAC46, VM49 and FZB42 showed highest inhibitory activity. A bioassay on detached rapeseed leaves demonstrated that strains VM10, EZ1509, FZB42 and GBAC46 were excellent in reducing lesion diameter, while, OKB105 and 168 were completely ineffective to control S. sclerotiorum. Interestingly, antifungal activity of Bacillus strains was positively co-related to the number of antimicrobial genes, indicating their role in antifungal activity of Bacillus strains. Our findings suggest that combining genetic markers and LC-MS analysis can rapidly screen Potential Bacillus strains with antifungal attributes and this screening method can serve as foundation for the development of new biopesticides.
  • Extract of Xanthomonas axonopodis induces resistance in Solanum tuberosum
           against Pectobacterium atrosepticum
    • Abstract: Publication date: Available online 14 March 2019Source: Biological ControlAuthor(s): Giulia Ramos Faillace, Eliane Romanato Santarém, Leandro Vieira AstaritaAbstractPotato (Solanum tuberosum) is affected by many pathogens, such as the necrotrophic bacterium Pectobacterium atrosepticum (Pba), resulting in substantial economic losses. The induction of natural disease resistance in crops using biological and chemical elicitors has received increasing attention in recent years, due to the low environmental toxicity of this method of disease management. We evaluated the ability of the autoclaved suspension of Xanthomonas axonopodis (XTH) to retard the disease caused by P. atrosepticum and the mechanism by which the elicitor promotes resistance, in detached leaves of S. tuberosum. Our results demonstrated that XTH slowed the progression and ameliorated the disease symptoms caused by P. atrosepticum. This effect may be related to the early activation of antioxidant enzymes such as catalase (CAT) at 0.5-hour post treatment (hpt), as well as to the activation of the defense-related enzymes, phenylalanine ammonia lyase (PAL) and chitinase at 24 hpt and 12 hpt, respectively. Leaves treated with XTH+Pba also showed increase in polyphenol oxidase activity at 96 hpt. Leaves pretreated with the biotic elicitor did not show increase on free SA level, differing from the those inoculated with Pba. Our results indicated that XTH induces the plant defense metabolism and delays the progression of disease in potato caused by P. atrosepticum.
  • Effects of releasing two Diachasmimorpha longicaudata population lines for
           the control of Ceratitis capitata infesting three key host fruit species
    • Abstract: Publication date: Available online 14 March 2019Source: Biological ControlAuthor(s): Lorena Suárez, María Josefina Buonocore Biancheri, Guillermo Sánchez, Fernando Murúa, Claudia F. Funes, Daniel S. Kirschbaum, Diego Molina, Osvaldo Laría, Sergio M. OvruskiExotic plants favor persistence and spread of the invasive medfly, Ceratitis capitata. Peach and orange are key host plants for medfly proliferation in Argentina. Consequently, actions to suppress medfly populations are taken, especially those performing augmentative releases of parasitoids. This study provides information on the capability of two population lines of the parasitoid Diachasmimorpha longicaudata to control medfly infesting the fruits of peach, as well as sour and sweet orange. One parasitoid line comes from non-irradiated larvae of wild medfly. The other comes from irradiated larvae of the Temperature Sensitive Lethal Vienna-8 medfly strain. The parasitoid host-finding ability in each aforementioned fruit species, the effectiveness of females to kill medfly larvae, the fruit height level preference for parasitoid foraging activity, and the influence of environmental conditions on parasitoid performance were compared and assessed. Parasitoids foraged for 48 h on fruits artificially inoculated with wild medfly larvae in field cages. Females of both parasitoid lines showed a similar effectiveness pattern, foraged efficiently on fruit at ground and canopy levels, and were able to overcome local climate conditions and to develop at least one new generation under natural environmental conditions. These outcomes may provide relevant information for the implementation of augmentative biological control against medfly.Graphical abstractGraphical abstract for this article
  • Food deprivation increases reproductive effort in a parasitoid wasp
    • Abstract: Publication date: Available online 14 March 2019Source: Biological ControlAuthor(s): Shun-ichiro Takano, Keiji TakasuAbstractLife history theory predicts that animals should increase their current reproductive effort as the probability of survival to the next reproductive opportunity decreases. We studied the effects of food depletion on life history and oviposition behavior in the egg parasitoid Paratelenomus saccharalis (Hymenoptera: Platygastridae) to determine if the parasitoid alters its reproductive strategy based on life expectancy. We first examined survivorship and reproductive effort of females provided only with water (i.e. starved) and females fed honey. Fed females lived up to 40 days, whereas starved females lived only up to 4 days. Fed females produced more offspring during life and had a higher net reproductive rate, i.e. R0, compared to starved females. Starved females did produce more offspring on the first day of emergence, however, and the intrinsic rate of natural increase, i.e. rm, did not differ between honey-fed and starved females. We further observed oviposition behavior in response to food availability during 24 hours on the first day of emergence to determine the mechanism by which starved females increased reproductive output. Results showed that starved females oviposited more frequently than honey-fed females, and that the time required for a single oviposition was shorter for starved females. These results revealed that starved females had higher oviposition rates on the first day of emergence, leading to the similar rm of starved and fed females. This indicates that P. saccharalis altered their oviposition behavior to maximize their fitness under food-depleted conditions.
  • Population dynamics of the Diamondback Moth and its parasitoids in
    • Abstract: Publication date: Available online 13 March 2019Source: Biological ControlAuthor(s): Rudo Sithole, Casper Nyamukondiwa, Peter Chinwada, Bernhard LohrAbstractTemporal population dynamics of the diamondback moth (DBM), Plutella xylostella (L.) and its parasitoids were studied for a continuous 13- months period at two sites in Zimbabwe, vis Henderson and Mutoko. Our results showed that mean DBM numbers of 2.2 and 2.9 per plant for Henderson and Mutoko, respectively were not significantly different (p = 0.12). At Henderson, the DBM numbers achieved a pre-winter peak in February and a post-winter peak in October, while at Mutoko the pre-winter and post-winter peaks were reached a month earlier, in January and September, respectively. A total of four parasitoid species, comprising Cotesia vestalis, Oomyzus sokolowskii, Brachymeria sp and Diadromus collaris were recorded from both Henderson and Mutoko. Cotesia vestalis predominated, accounting for over 98% parasitism at both sites. Mean parasitism rates of 40.6 and 29.3% were recorded at Henderson and Mutoko, respectively, and these were significantly different. Maximum parasitism rates were reached during the post-winter period at both sites with values of 86.4 (December) and 58% (September) for Henderson and Mutoko, respectively. For Henderson, percentage parasitism was positively correlated with both maximum and minimum temperature and DBM density was positively correlated with maximum temperature. For Mutoko neither DBM density nor percent parasitism was significantly correlated with either maximum or minimum temperature. Mean rainfall did not have any effect on host density or parasitism rates at both sites. For both sites parasitism was host density dependent. These results are significant in explaining factors limiting abundance of DBM-parasitoids and may help shape future biocontrol programmes.
  • Effects of photoperiod and light intensity on wing dimorphism and
           development in the parasitoid Sclerodermus pupariae (Hymenoptera:
    • Abstract: Publication date: Available online 4 March 2019Source: Biological ControlAuthor(s): Shuai Hu, Xiao-Yi Wang, Zhong-Qi Yang, Jian J. DuanSclerodermus pupariae Yang et Yao (Hymenoptera: Bethylidae), a newly described ectoparasitoid, has been used as a biocontrol agent against several buprestid and cerambycid pests in China. Both winged and wingless female morphs of S. pupariae can find and parasitize hosts; however, winged parasitoids can disperse faster and further to new habitats and thus are more adapted to spatial and temporal changes in host densities than wingless morphs. In the present study, we determined the effects of photoperiod and associated light intensity on the parasitoid development time from egg to adult, the proportion of winged females, fecundity, and progeny sex ratio. Significantly more winged female parasitoid progeny were produced with long-day photoperiods and high light intensity compared to short day-photoperiods and low light intensity treatments. Photoperiod alone (regardless of light intensity) has significant impact on developmental time of parasitoid progeny. Light intensity, interacted with photoperiod, significantly affected the degree of phenotypic partitioning and development time, but light intensity and photoperiod did not significantly influence the parasitoid fecundity and sex ratio. These results are relevant to laboratory rearing of S. pupariae when the optimal light conditions are needed to produce winged female parasitoids.Graphical abstractGraphical abstract for this article
  • Efficacy of arbuscular mycorrhizal fungi and endophytic strain Epicoccum
           nigrum ASU11 as biocontrol agents against blackleg disease of potato
           caused by bacterial strain Pectobacterium carotovora subsp. atrosepticum
    • Abstract: Publication date: Available online 4 March 2019Source: Biological ControlAuthor(s): Hadeel M.M Khalil Bagy, Elhagag Ahmed Hassan, Nivien Allam Nafady, Mona F.A. DawoodAbstractThis work was aimed to evaluate the efficacy of arbuscular mycorrhizal fungi (AMF) and the endophytic fungal strain Epicoccum nigrum ASU11 (Epi) to control potato blackleg caused by bacterial stain Pectobacterium carotovora subsp. atrosepticum PHY7 (Pca). E. nigrum showed unique colonization frequency properties of potato plants (73.3 % colonization frequency). Furthermore, the endophytic fungus exhibited antagonistic capability against pathogenic bacteria with inhibition zone 18 ± 0.5 mm. The AMF and Epi individually or in combination reduced Pca population in vivo experiment. The highest level of reduction was recorded in combination of AMF+ Epi. Also, infected potato plants treated with the two bioagents showed the highest weight of potato tubers in comparison to infected control. The enhancement of potato plants growth and the elevation of blackleg disease symptoms by bioagents (Epi + AMF) could be attributed to promoting the systemic plant resistance through the decrease of reactive oxygen species (ROS), malondialdehyde content (MDA), glutathione-S- transferase (GST), soluble peroxidase (SPO), ionic peroxidase (IPO), polyphenol oxidase (PPO), phenyl alanine ammonialyase (PAL) and lignin content. Moreover, they enhance the content of potato phenolics, superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione peroxidase (GPX) content. These results detected the potentiality of AMF and E. nigrum to promote potato growth and decrease the disease severity of blackleg disease. These biocontrol agents may have promising prospective strategies in potato crop protection and increase the feasibility of agriculture crop protection. The results reported herein are expected to provide competitive economic outcomes for sustainable cropping protection systems.
  • Coccinellid host morphology dictates morphological diversity of the
           parasitoid wasp Dinocampus coccinellae
    • Abstract: Publication date: Available online 26 February 2019Source: Biological ControlAuthor(s): Hannah Vansant, Yumary M Vasquez, John J Obrycki, Arun SethuramanDraft text for the abstract – this is a little wordy – but I think it gets us started ''Pararsitoid-host interactions involving host species that are newly introduced into the range of a generalist parasitoid provide systems that can be examined for phentypic plasticity and evolutionary changes in parasitoid-host dynamics. The solitary Bracond parasitoid wasp, Dinocampus coccinellae, has a cosmopolitan distribution and attacks approximately 50 species of predatory lady beetles (ladybirds) in the family Coccinellidae. In this study we quantified the effect of six (4 native North American and 2 non-native North American) host species on the morphometrics of D. coccinellae. Adult lady beetles were collected from 13 locations in the United States and reared in the laboratory until D.coccinellae exited from their adult beetle hosts. Eighty-nine individual D. coccinellae females and their associated host were weighed and morphometric measurements were taken. The smallest lady beetle host Hippodamia parenthesis produced the smallest adult wasps; the largest host species, Coccinella septempunctata, produced the largest female wasps. A directional cline in morphology of wasps and their coccinellid hosts was also observed in a dry-weight regression (R2 = 0.4066, p-value < 0.0001). Two underlying mechanisms may explain the results of our study: (1) morphometric variation in D. coccinellae is governed by phenotypic plasticity with the size of the emerging offspring contingent on the size of the coccinellid host, and/or (2) that morphometric variation in D. coccinellae is governed by genomic adaptation to coccinellid host populations
  • Conceptualizing, categorizing and recording the outcomes of biological
           control of invasive plant species, at a population level
    • Abstract: Publication date: Available online 8 February 2019Source: Biological ControlAuthor(s): John H. Hoffmann, V. Cliff Moran, Martin P. HillAbstractRates of establishment of agents, their population dynamics after release, and measures of the damage they inflict on their target hosts are all useful indicators of progress and success in weed biological control but cannot account for the overall degree and extent of weed biocontrol achievements (i.e. outcomes) at a plant population level. Current conventions that describe weed biocontrol outcomes as ‘negligible’, ‘partial’, ‘substantial’ or ‘complete’, are often idiosyncratic and imprecise and are inadequate for describing the complexities involved. Using selected examples from South Africa, an extension of the present system is proposed for conceptualizing and categorizing weed biocontrol outcomes more easily; it incorporates four different invasion parameters i.e. density, area, biomass and number of propagules, for different regions and habitats. This approach should help to provide weed biocontrol practitioners with a shared basis for describing, succinctly and with greater precision, the results of their weed biocontrol programs, at a plant population level.
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