Publisher: Oxford University Press (Total: 369 journals)
Journal of Insect Science
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Open Access journal
ISSN (Print) 1536-2442
Published by Oxford University Press [369 journals]
- Aggregation Behavior and a Putative Aggregation Pheromone in Sugar Beet
Root Maggot Flies (Diptera: Ulidiidae)
Authors: Wenninger EJ; Emmert SY, Tindall K, et al.
Abstract: Male-biased aggregations of sugar beet root maggot, Tetanops myopaeformis (Röder) (Diptera: Ulidiidae), flies were observed on utility poles near sugar beet (Beta vulgaris L. [Chenopodiaceae]) fields in southern Idaho; this contrasts with the approximately equal sex ratio typically observed within fields. Peak observation of mating pairs coincided with peak diurnal abundance of flies. Volatiles released by individual male and female flies were sampled from 08:00 to 24:00 hours in the laboratory using solid-phase microextraction and analyzed using gas chromatography/mass spectrometry (GC/MS). Eleven compounds were uniquely detected from males. Three of these compounds (2-undecanol, 2-decanol, and sec-nonyl acetate) were detected in greater quantities during 12:00–24:00 hours than during 08:00–12:00 hours. The remaining eight compounds uniquely detected from males did not exhibit temporal trends in release. Both sexes produced 2-nonanol, but males produced substantially higher (ca. 80-fold) concentrations of this compound than females, again peaking after 12:00 hours. The temporal synchrony among male aggregation behavior, peak mating rates, and release of certain volatile compounds by males suggest that T. myopaeformis flies exhibit lekking behavior and produce an associated pheromone. Field assays using synthetic blends of the putative aggregation pheromone showed evidence of attraction in both females and males.
- Bioactivity of Novel Botanical Insecticide From Gnidia kaussiana
(Thymeleaceae) Against Callosobruchus maculatus (Coleoptera:
Chrysomelidae) in Stored Vigna subterranea (Fabaceae) Grains
Authors: Kosini DD; Nukenine EN.
Abstract: Hexane, acetone, and methanol extracts from Gnidia kaussiana Meisn (Thymeleaceae), each at two dosages (0.2 and 1 ml/50 g grains corresponding, respectively to 1 and 5g/kg), and neem seed oil (NSO), used as standard insecticide were evaluated for repellence, toxicity to Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) adults, F1 progeny inhibition, persistence and as grain protectant during storage. Experiments were laid out at complete randomized design with five replications for repellence test and four for others. All the extracts were effective in protecting stored Bambara groundnut (Vigna subterranea (L.) Verdcourt) from insect attack; however, their bioactivities were inversely correlated with solvent polarity. No adult survival was recorded in treated grains with hexane extract at 5 g/kg dosage within 2 d exposure. Also at 5 g/kg, all extracts hindered adults emergence, grain damage and weight loss after 4 months storage. Moreover, hexane extract was more repellent and exhibited averagely repellency. The insecticidal effectiveness of hexane extract did not decreased provided that the exposure time of insects to the product was high (7 d). The potency of acetone and methanol extracts decreased with storage time, although not linearly and remained significantly toxic to C. maculatus up to 60 d of storage. Therefore, hexane and acetone extracts are good candidates for incorporation in integrated pest management programs for control of cowpea weevils in stored grains by poor-resourced farmers and store keepers in Cameroon and other developing countries.
- Field Evaluation of Potential Pheromone Lures for Lygus lineolaris
(Hemiptera: Miridae) in the Mid-South
Authors: Parys KA; Hall DR.
Abstract: Plant bugs (Hemiptera: Miridae) are phytophagous pests of cultivated plants around the world. In the mid-South region of the United States, Lygus lineolaris (Palisot de Beauvois) is a primary pest of cotton, and causes economic damage. Previously published research about the volatiles produced by members of the genus Lygus, and other closely related groups, indicated that they produce blends of hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal. Varying ratios of the three compounds were loaded into pipette tips, and screened in combination with non-UV white sticky cards for attractiveness to field populations of L. lineolaris in Mississippi. Field screening indicated that a lure expressing a ratio of 4:10:7 was the most effective at collecting L. lineolaris, and collected similar numbers of individuals to those reported in other studies using traps baited with live virgin insects over a similar period of time. Availability of a synthetic pheromone usable in the climate of the mid-South will enable broader scale landscape level monitoring for populations of L. lineolaris before movement into cotton fields and resulting economic damage.
- Immunological Responses of Sesamia cretica to Ferula ovina Essential Oil
Authors: Sadeghi R; Hadizadeh Raeisi N, Jamshidnia A.
Abstract: The current research was performed aiming to investigate the effects of Ferula ovina essential oil on the fourth instar larval hemogram of Sesamia cretica. Four main sorts of circulating hemocytes, including prohemocytes, plasmatocytes, granulocytes (GRs), and oenocytoides, were identified in the fourth instar larvae. Treatment of the larvae with the concentration of 1000 ppm of the essential oil led to an enhancement of the total hemocyte and GR count followed by a dose-dependent decrease at the concentrations of 2500 and 7000 ppm. Plasmatocyte numbers declined in all the treatments with more significant effects at increased doses. The greatest numbers of GRs, plasmatocytes, and total hemocytes were found after 48 h of treatment. The highest phenol-oxidase activity was recorded 12 h after treatment at the concentration of 2500 ppm. The highest effect on nodule formation was exerted by the concentration of 7000 ppm 12 h after treatment. The results of the present study clearly indicated that the treatment of larvae by the essential oil of F. ovina decreased the numbers of total and differential hemocyte counts although phenol-oxidase activity and the number of nodules showed no decline in the treated larvae. These results demonstrated that Ferula ovina essential oil has a significant effect on the immune ability of the studied insect and can be useful and usable for future research to practical management of this pest.
- Influence of Temperature and Relative Humidity on the Insecticidal
Efficacy of Metarhizium anisopliae against Larvae of Ephestia kuehniella
(Lepidoptera: Pyralidae) on Wheat
Authors: Athanassiou CG; Kavallieratos NG, Rumbos CI, et al.
Abstract: A series of laboratory bioassays were conducted for the evaluation of the insecticidal efficacy of an isolate of Metarhizium anisopliae (Metschnikoff) Sorokin (Ascomycota: Hypocreales) against larvae of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), under various temperature–relative humidity (r.h.) conditions. The fungus was applied at four doses (0, 8 × 106, 8 × 108, and 8 × 1010 conidia ml−1) on wheat and insect mortality was assessed after exposure of 1, 2, 7, and 14 d. Bioassays were conducted at three temperatures (20, 25, and 30 °C) and two r.h. levels (55 and 75%). Although complete control was not achieved in any case, the fungus provided a considerable level of insect control. Mortality of E. kuehniella larvae on wheat treated with M. anisopliae ranged between 41.1 and 93.3% after 14 d of exposure, whereas the respective mortality levels in control dishes never exceeded 28.3%. The increase of temperature resulted in most cases to higher efficacy, indicating that temperature is an important factor for the performance of the fungus. In contrast, in most cases r.h. did not significantly affect the efficacy of the fungus, at least for the humidity levels tested.
- Invertebrates, Fungal Biomass, and Leaf Breakdown in Pools and Riffles of
Authors: Tavares Martins R; Souza da Silveira L, Pereira Lopes M, et al.
Abstract: We evaluated fungal biomass (as ergosterol concentration) and invertebrate colonization during leaf breakdown of Picramnia sellowii Planch. (Picramniaceae) in pools and riffles of three low-order forested streams in southeastern Brazil. We hypothesized that leaf breakdown will be higher in riffles due to the high physical fragmentation and fungal activity. The experiment was carried out during the dry season of 2012, using 108 litter bags, each containing 3 ± 0.05 g of air-dried leaves. After 7, 15, 30, 60, 90, and 120 d of incubation, six litter bags (riffle = 3 and pool = 3) were removed from each stream. Leaf breakdown rate (k) was classified as intermediate in pools and fast in riffles. We recorded similar values of remaining leaf mass in two habitats until 60 d. However, at 90 and 120 d, this process was faster in riffles. The mean fungal biomass was similar between habitats and showed an increase during the experiment at 90 d. Fauna composition differed between habitats and across sampling dates, with Chironomidae most contributing to these differences and being particularly abundant in riffles and in the initial period of leaf breakdown (until 30 d). Shredder abundance and biomass were not different between habitats and among incubation durations. Leaf breakdown (remaining leaf mass) was positively associated with fungal and shredder biomasses. However, water velocity was not related to leaf breakdown. These findings emphasize the importance of fungal and shredder organisms, as well as the low importance of water velocity, on mass loss in low-order tropical streams.
- Modeling Temperature-Dependent Development of Glyphodes pyloalis
Authors: Moallem Z; Karimi-Malati A, Sahragard A, et al.
Abstract: Development of Glyphodes pyloalis Walker was studied under laboratory conditions at constant temperatures of 12, 16, 20, 24, 28, 30, 32, and 36 °C. No development occurred at 36 °C. Although eggs hatched at 12 ºC, no larvae were capable of developing to adult stage. At 16 ºC, survival rate was low (4%) and prepupal stage lasted 101.68 ± 11.03 d. Larvae completed development through six stadia at 16, 30, and 32 °C. Developmental time of overall immature stages varied from 46.62 d at 20 °C to 22.04 d at 30 °C and increased at 32 °C. The lower temperature thresholds of 10.30 and 11.22 °C, and thermal constants of 429.18 and 401.88 DD were estimated by traditional and Ikemoto–Takai linear models, respectively. The Tmin values estimated by Analytis, Briere-2, Lactin-2, and Sharpe–Schoolfield–Ikemoto (SSI) for overall immature stages were 12.40, 12.92, 9.00, and 13.04 °C, respectively. The fastest development temperatures (Tfast) of 31.1, 31.1, 30.8, and 30.7 °C were estimated for overall immature stages based on Analytis, Briere-2, Lactin-2, and SSI, respectively. The intrinsic optimum temperature (Topt) estimated from the thermodynamic SSI model for total developmental time was 24.63 °C, in which the maximal active state enzymes involved in developmental process. The nonlinear models of Analytis, Lactin-2, Briere-2, and SSI estimated the upper temperature thresholds (Tmax) at 36.66, 35.97, 38.88, and 34.05 °C, respectively. These ﬁndings could be used to predict the population dynamics of G. pyloalis for an effective management.
- The Invasive Liriomyza huidobrensis (Diptera: Agromyzidae): Understanding
Its Pest Status and Management Globally
Authors: Weintraub PG; Scheffer SJ, Visser D, et al.
Abstract: Liriomyza huidobrensis (Blanchard) is native to South America but has expanded its range and invaded many regions of the world, primarily on flowers and to a lesser extent on horticultural product shipments. As a result of initial invasion into an area, damage caused is usually significant but not necessarily sustained. Currently, it is an economic pest in selected native and invaded regions of the world. Adults cause damage by puncturing abaxial and adaxial leaf surfaces for feeding and egg laying sites. Larvae mine the leaf parenchyma tissues which can lead to leaves drying and wilting. We have recorded 365 host plant species from 49 families and more than 106 parasitoid species. In a subset of the Argentinian data, we found that parasitoid community composition attacking L. huidobrensis differs significantly in cultivated and uncultivated plants. No such effect was found at the world level, probably due to differences in collection methods in the different references. We review the existing knowledge as a means of setting the context for new and unpublished data. The main objective is to provide an update of widely dispersed and until now unpublished data, evaluate dispersion of the leafminer and management strategies in different regions of the world, and highlight the need to consider the possible effects of climate change on further regional invasions or expansions.
- Temporal Resource Partitioning and Interspecific Correlations in a Warm,
Temperate Climate Assemblage of Dung Beetles (Coleoptera: Scarabaeidae)
Authors: Sullivan GT; Ozman-Sullivan SK, Bourne A, et al.
Abstract: Guilds of dung dwelling and tunneling dung beetles coexist in local assemblages in warm temperate regions, despite the tendency of dwellers to be inferior competitors. A field experiment on the Black Sea coast of Turkey examined the role of temporal resource partitioning in their coexistence. Standardized dung pads deposited at 4 h intervals through a 24 h period in summer were collected 12, 24, or 48 h later. Adults from 10 tunneling and seven dung dwelling species were collected. The tunnelers contributed a high proportion of both total abundance and biomass. There was a significant effect of dung deposition time and exposure period on mean tunneler abundance. Mean tunneler abundance was nearly seven times higher in dung deposited at 06:00 than at 18:00. The dwellers reduced the potential for competitive interactions with tunnelers by relatively uniform dispersal across the six dung deposition times. The distinctly different dung use patterns by dwellers and tunnelers demonstrated temporal resource partitioning. Interspecific correlation coefficients were also determined because interspecific relationships are at the core of resource partitioning. Total tunneler and dweller abundances were not correlated. Overall, there were strong positive correlations between tunneling species and low correlations between tunneling and dwelling species, and between dwelling species. The five most abundant tunnelers, from two tribes and three genera, were strongly positively correlated. There were substantial size differences among the four most abundant tunnelers that probably facilitate their coexistence.
- Efficacy of Some Wearable Devices Compared with Spray-On Insect Repellents
for the Yellow Fever Mosquito, Aedes aegypti (L.) ( Diptera: Culicidae )
Authors: Rodriguez SD; Chung H, Gonzales KK, et al.
Abstract: The current Zika health crisis in the Americas has created an intense interest in mosquito control methods and products. Mosquito vectors of Zika are of the genus Aedes, mainly the yellow fever mosquito, Aedes aegypti. L. The use of repellents to alter mosquito host seeking behavior is an effective method for the prevention of mosquito-borne diseases. A large number of different spray-on repellents and wearable repellent devices are commercially available. The efficacies of many repellents are unknown. This study focuses on the efficacy of eleven different repellents in reducing the number of Ae. aegypti female mosquitoes attracted to human bait. We performed attraction-inhibition assays using a taxis cage in a wind tunnel setting. One person was placed upwind of the taxis cage and the mosquito movement towards or away from the person was recorded. The person was treated with various spray-on repellents or equipped with different mosquito repellent devices. We found that the spray-on repellents containing N,N-Diethyl-meta-toluamide and p-menthane-3,8-diol had the highest efficacy in repelling mosquitoes compared to repellents with other ingredients. From the five wearable devices that we tested, only the one that releases Metofluthrin significantly reduced the numbers of attracted mosquitoes. The citronella candle had no effect. We conclude that many of the products that we tested that were marketed as repellents do not reduce mosquito attraction to humans.
- A New Report of Nezara viridula f. aurantiaca (Heteroptera: Pentatomidae)
from a Cultured Population in Washington County, Mississippi
Authors: Rojas M; Morales-Ramos JA.
Abstract: Nezara viridula adult coloration can vary, including a rare orange-colored type (i.e., N. viridula f. aurantiaca). In November 2015, three Nezara viridula males displaying orange coloration were found in an established colony in Stoneville, MS. The objectives of this study were to determine if alleles of these orange types conformed to the allele characteristics previously reported for N. viridula f. aurantiaca and to determine if there were any differences in reproductive output compared with the green-colored type. The three orange-type males were crossed with green-type females to produce a hybrid F1. The F1 progeny was allowed us to cross to produce an F2. The F2 progeny consisted of 672 green females, 351 green males, 298 orange males, and 0 orange females. These ratios did not differ significantly from the expected 50:25:25:0 ratios for a single recessive sex linked allele for color phenotype. The F2 cross of green females and orange males produced an F3 consisting of 345 green females, 346 green males, 100 orange females, and 85 orange males. These ratios also conformed to the expected ratios (0.375:0.375:0.125:0.125) with the exception of orange males, which numbers were slightly lower than expected. The pure orange type N. viridula produced significantly less egg masses (0.71 ± 0.15) per day than green types (2.09 ± 0.16) and their reproductive output, measured as net reproductive rate (Ro), was lower in orange (13.71) compared with green (20.67) types.
- Boxwood Borer Heterobostrychus brunneus (Coleoptera: Bostrichidae)
Infesting Dried Cassava: A Current Record from Southern Ethiopia
Authors: Parmar A; Kirchner SM, Langguth H, et al.
Abstract: Insect specimens of adult beetles and larvae of 7–9 and 9–10 mm length, respectively were collected from infested dry cassava at two locations from multiple stores in southern Ethiopia. The specimens were identified as Heterobostrychus brunneus (Murray, 1867) commonly known as boxwood borer and auger beetle. The study presents a current record of H. brunneus in Ethiopia, particularly in the context of infesting food products. Additionally, a wide geographical distribution of the pest was reviewed and presented in this article. Current evidence suggests that H. brunneus is a serious pest of forest wood, structural timbers, and dried food products and that it carries a risk to be introduced into various other parts of the world via global trade.
Abstract: Corrections of “A descriptive morphology of the ant genus Procryptocerus (Hymenoptera: Formicidae). Journal of Insect Science 10: 111”
DOI : 10.1673/031.010.11101.
- A comparison of trapping techniques (Coleoptera: Carabidae, Buprestidae,
Cerambycidae, and Curculionoidea excluding Scolytinae)
Authors: Skvarla MJ; Dowling AG.
Abstract: Beetles (Coleoptera) are a charismatic group of insects targeted by collectors and often used in biodiversity surveys. As part of a larger project, we surveyed a small (4 hectare) plot in the Boston Mountains of Arkansas using 70 traps of 12 trap types and Berlese–Tullgren extraction of leaf litter and identified all Buprestidae, Carabidae, Cerambycidae, and Curculionoidea (Anthribidae, Attelabidae, Brachyceridae, Brentidae, and Curculionidae excluding Scolytinae) to species. This resulted in the collection of 7,973 specimens representing 242 species arranged in 8 families. In a previous publication, we reported new state records and the number of specimens collected per species. In this publication, we used these data to determine the most effective collection method for four beetle groups: Carabidae, Cerambycidae, Curculionoidea (excluding Scolytinae), and Buprestidae. We found that the combination of pitfall and Malaise traps was most effective for Carabidae, Cerambycidae, and Curculionoidea, but that the combination of Malaise and green Lindgren funnel traps was most effective at collecting Buprestidae. Species accumulation curves did not become asymptotic and extrapolated rarefaction curves did not become asymptotic until 350–1,000 samples, suggesting that much more effort is required to completely inventory even a small site. Additionally, seasonal activity is presented for each species and the similarity and overlap between collecting dates and seasons is discussed for each family.
- An Old Remedy for a New Problem? Identification of Ooencyrtus kuvanae
(Hymenoptera: Encyrtidae), an Egg Parasitoid of Lycorma delicatula
(Hemiptera: Fulgoridae) in North America
Authors: Liu H; Mottern J.
Abstract: Spotted Lanternfly, Lycorma delicatula (White) is a recently introduced pest of Tree-of-Heaven, Ailanthus altissima (Mill.) Swingle in North America. Natural enemy surveys for this pest in Pennsylvania in 2016 recovered an encyrtid egg parasitoid from both field collections and laboratory rearing of field-collected L. delicatula egg masses. Both molecular and morphological data confirm that the egg parasitoids are Ooencyrtus kuvanae (Howard) (Hymenoptera: Encyrtidae). Ooencyrtus kuvanae (Howard) is primarily an egg parasitoid of gypsy moth, Lymantria dispar (L.), and was introduced to North America in 1908 for gypsy moth biological control. Although O. kuvanae is known to attack multiple host species, to our knowledge, this is the first report of O. kuvanae as a primary parasitoid of a non-lepidopteran host. Potential of O. kuvanae in the biological control of L. delicatula in North America and research needs are discussed.
- Augmenting Laboratory Rearing of Stable Fly (Diptera: Muscidae) Larvae
With Ammoniacal Salts
Authors: Friesen K; Berkebile DR, Zhu JJ, et al.
Abstract: Stable flies are blood feeding parasites and serious pests of livestock. The immature stages develop in decaying materials which frequently have high ammonium content. We added various ammonium salts to our laboratory stable fly rearing medium and measured their effect on size and survival as well as the physical properties of the used media. The addition of ammonium hydroxide, ammonium phosphate and ammonium sulfate reduced larval survival. These compounds decreased pH and increased ammonium content of the used media. Ammonium bicarbonate had no effect on pH and marginally increased ammonium while increasing survival twofold. The optimal level of ammonium bicarbonate was 50 g (0.63 mol) per pan. Larval survival decreased when pH was outside the range of 8.5 to 9.0.
- Dispersal of Amblyseius swirskii (Acari: Phytoseiidae) on High-Tunnel Bell
Peppers in Presence or Absence of Polyphagotarsonemus latus (Acari:
Authors: Lopez LL; Smith HA, Hoy MA, et al.
Abstract: Amblyseius swirskiiAthias-Henriot (Acari: Phytoseiidae) is a predatory mite used to control thrips (Thysanoptera), whiteflies (Bemisia tabaci Genn., Hemiptera: Aleyrodidae), and broad mites (BMs) (Polyphagotarsonemus latus Banks, Acari: Tarsonemidae). Dispersal of A. swirskii, using the ornamental pepper “Explosive Ember” as a banker plant was evaluated for control of BMs in high-tunnel peppers. Open-canopy plants (5 weeks old) versus closed-canopy plants (10-weeks old) were used to evaluate the effect of plant connectedness in A. swirskii dispersal, in the presence (two females per plant) and absence of BMs. Plots consisted of a single central banker plant and four bell peppers extending linearly north and south. Sets of all treatments were destructively sampled 1, 4, and 7 days after releasing A. swirskii. Within 24 h, A. swirskii dispersed four plants away from the banker plants (1 m), regardless of the state of the canopy. Canopy connectedness did increase the presence of A. swirskii on the crop plants. Predatory mite numbers on closed-canopy treatments doubled within the 7-day sampling period, whereas no significant increase was observed on open-canopy treatments. The presence of BMs had no significant effect on the movement of A. swirskii. The results suggest further experiments with A. swirskii and banker plants for control of BMs is warranted.
- Dynamics of Reintroduced Populations of Oedipoda caerulescens (Orthoptera,
Acrididae) over 21 Years
Authors: Baur B; Thommen G, Coray A.
Abstract: Conservation programs increasingly involve the reintroduction of animals which otherwise would not recolonize restored habitats. We assessed the long-term success of a project in which the Blue-winged grasshopper, Oedipoda caerulescens (L., 1758), was reintroduced to a nature reserve in Northwestern Switzerland, an alluvial gravel area where the species went extinct in the 1960s. In summer 1995, we released 110 individuals (50 females and 60 males) and 204 individuals (101 females and 103 males) into two restored gravel patches with sparse vegetation. We used a transect count technique to assess the population size of O. caerulescens in the years 1995–2004 and 2015–2016 and recorded the area occupied by the species. At both release sites, the populations persisted and increased significantly in size. Individuals that followed a newly created corridor established four new subpopulations. Seven years after reintroduction, O. caerulescens had reached a high abundance around the release sites and in the four colonized patches, indicating a successful project. At the same time, the dispersal corridor became increasingly overgrown by dense vegetation. Surveys 20 and 21 yr after introduction showed that the abundance of the Blue-winged grasshopper had strongly declined in the established subpopulations and moderately in the original release sites, owing to natural succession of the habitat and lack of disturbances, which reduced the area suitable for the species by 59%. Our study shows that reintroductions are unlikely to succeed without integration of long-term habitat management (in the present case maintenance of open ground).
- Genetic Diversity in Nannotrigona testaceicornis (Hymenoptera: Apidae)
Aggregations in Southeastern Brazil
Authors: Fonseca AS; Oliveira EF, Freitas GS, et al.
Abstract: The Meliponini, also known as stingless bees, are distributed in tropical and subtropical areas of the world and plays an essential role in pollinating many wild plants and crops These bees can build nests in cavities of trees or walls, underground or in associations with ants or termites; interestingly, these nests are sometimes found in aggregations. In order to assess the genetic diversity and structure in aggregates of Nannotrigona testaceicornis (Lepeletier), samples of this species were collected from six aggregations and genetically analyzed for eight specific microsatellite loci. We observed in this analysis that the mean genetic diversity value among aggregations was 0.354, and the mean expected and observed heterozygosity values was 0.414 and 0.283, respectively. The statistically significant Fis value indicated an observed heterozygosity lower than the expected heterozygosity in all loci studied resulting in high homozygosis level in these populations. In addition, the low number of private alleles observed reinforces the absence of structuring that is seen in the aggregates. These results can provide relevant information about genetic diversity in aggregations of N. testaceicornis and contribute to the management and conservation of these bees’ species that are critical for the pollination process.
- Geographic Origin and Host Cultivar Influence on Digestive Physiology of
Spodoptera exigua (Lepidoptera: Noctuidae) Larvae
Authors: Golikhajeh N; Naseri B, Razmjou J.
Abstract: Digestive enzymatic activity in three geographic strains (Miandiab, Kalposh and Moghan regions) of Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) reared on different sugar beet cultivars (Dorothea, Rozier, Persia and Perimer) was studied under laboratory conditions (25 ± 1 °C, 65 ± 5% RH, and a photo period of 16:8 (L:D) h photoperiod). The results of this study demonstrated that digestive protease and amylase activity of S. exigua larvae was affected by both geographic origin of the pest and host plant cultivar. Three strains reared on the same sugar beet cultivars demonstrated different levels of proteolytic and amylolytic activities in fourth and fifth instars. The highest proteolytic and amylolytic activity, in most cases, was observed in larvae collected from Kalposh region. Among different sugar beet cultivars, the highest protease activity in three strains was observed on cultivars Rozier and Perimer. Nevertheless, the highest amylase activity was seen on cultivar Dorothea, and the lowest activity was seen on cultivar Rozier. This study suggested that variations in digestive enzymatic activity of three geographic strains of S. exigua might be attributed to local adaptation with their local host plant and environmental conditions inherent by larvae.
- High Elevation Refugia for Bombus terricola (Hymenoptera: Apidae)
Conservation and Wild Bees of the White Mountain National Forest
Authors: Tucker EM; Rehan SM.
Abstract: Many wild bee species are in global decline, yet much is still unknown about their diversity and contemporary distributions. National parks and forests offer unique areas of refuge important for the conservation of rare and declining species populations. Here we present the results of the first biodiversity survey of the bee fauna in the White Mountain National Forest (WMNF). More than a thousand specimens were collected from pan and sweep samples representing 137 species. Three species were recorded for the first time in New England and an additional seven species were documented for the first time in the state of New Hampshire. Four introduced species were also observed in the specimens collected. A checklist of the species found in the WMNF, as well as those found previously in Strafford County, NH, is included with new state records and introduced species noted as well as a map of collecting locations. Of particular interest was the relatively high abundance of Bombus terricola Kirby 1837 found in many of the higher elevation collection sites and the single specimen documented of Bombus fervidus (Fabricius 1798). Both of these bumble bee species are known to have declining populations in the northeast and are categorized as vulnerable on the International Union for Conservation of Nature’s Red List.
- Laboratory Bioassays with Three Different Substrates to Test the Efficacy
of Insecticides against Various Stages of Drosophila suzukii (Diptera:
Authors: Pavlova A; Dahlmann M, Hauck M, et al.
Abstract: Rapid worldwide spread and polyphagous nature of the spotted wing Drosophila Drosophila suzukii Matsumura (Diptera: Drosophilidae) calls for efficient and selective control strategies to prevent severe economic losses in various fruit crops. The use of insecticides is one option for management of this invasive pest insect. Efficacy of insecticides is usually assessed first in laboratory bioassays, which are compounded by the cryptic nature of D. suzukii larvae and the fact that fruits used in bioassays often start to rot and dissolve before larvae have reached the adult stage. Here, we report on laboratory bioassays using three different types of substrates allowing a thorough screening of insecticides for their potential effects against D. suzukii eggs, larvae and adults. Suitability of our bioassays was validated in an assessment of the efficacy of four bioinsecticides and one synthetic insecticide against various developmental stages of D. suzukii. Water-apple juice agar used as a bioassay substrate allowed egg counting and observation of larval development due to its transparency, while apple-nutrition medium allowed complete metamorphosis. Use of grape berries in bioassays made it possible to assess effects of an insecticide present on a fruit’s surface on oviposition and larval hatch from eggs. Insecticides tested in these three different bioassays with acetamiprid, spinosad or natural pyrethrins as active ingredients achieved a significant D. suzukii control if they were applied before egg deposition. Number of adult flies was significantly reduced if the bioassay medium was treated with an azadirachtin A containing insecticide both before or after egg deposition.
- Morphology of the Male Reproductive System and Spermiogenesis of
Dendroctonus armandi Tsai and Li (Coleoptera: Curculionidae: Scolytinae)
Authors: Wu Y; Wei L, Anthony Torres M, et al.
Abstract: Studying the reproductive attributes of pests is central to understanding their life cycle history and in crafting management strategies to regulate, if not bring down, their population below threshold levels. In this article, the morphology of the male reproductive tract, topology of the spermatozoa, and salient features of spermiogenesis in the Chinese white pine beetle, Dendroctonus armandi Tsai and Li was studied to provide baseline information for further pest management studies. Results showed that male reproductive tract of this species differs from those documented in other Coleopterans by having 20 testicular tubules in each testis and the presence of two types of accessory glands. The spermatozoon is seen having peculiar characteristics such as an “h”-shaped acrosomal vesicle with a “puff”-like expansion, one centriole, one large spongy body, and two accessory bodies. Despite with some morphological differences of the male reproductive organ, spermatogenesis in this organism is similar to other Coleopterans. Overall, detailed studies regarding the components of the primary male reproductive organ of this beetle species would expand the knowledge on the less-understood biology of Coleopteran pests and would help in designing regulatory measures to conserve endemic and indigenous pine trees in China.
- Quantitative Trait Loci and Antagonistic Associations for Two
Developmentally Related Traits in the Drosophila Head
Authors: Norry FM; Gomez FH.
Abstract: In insects, some developmentally related traits are negatively correlated. Here, we mapped Quantitative Trait Loci (QTL) for traits of eye size and head capsule, in an intercontinental set of recombinant inbred lines (RILs) of Drosophila melanogaster. Composite interval mapping identified QTL on all major chromosomes. Two negatively correlated traits (size of eyes and between-eyes distance) were influenced by one QTL that appeared to be antagonistic between the traits (QTL cytological range is 25F5–30A6), consistent with a negative genetic correlation between these traits of the head capsule. Comparisons of QTL across traits indicated a nonrandom distribution over the genome, with a considerable overlap between some QTL across traits. Developmentally-related traits were influenced by QTL in a pattern that is consistent both with 1) the sign of the genetic correlation between the traits and 2) a constraint in the micro-evolutionary differentiation in the traits.
- Rice Stripe Virus Infection Alters mRNA Levels of
Sphingolipid-Metabolizing Enzymes and Sphingolipids Content in Laodelphax
Authors: Jiao W; Li F, Bai Y, et al.
Abstract: Sphingolipids and their metabolites have been implicated in viral infection and replication in mammal cells but how their metabolizing enzymes in the host are regulated by viruses remains largely unknown. Here we report the identification of 12 sphingolipid genes and their regulation by Rice stripe virus in the small brown planthopper (Laodelphax striatellus Fallén), a serious pest of rice throughout eastern Asia. According to protein sequence similarity, we identified 12 sphingolipid enzyme genes in L. striatellus. By comparing their mRNA levels in viruliferous versus nonviruliferous L. striatellus at different life stages by qPCR, we found that RSV infection upregulated six genes (LsCGT1, LsNAGA1, LsSGPP, LsSMPD4, LsSMS, and LsSPT) in most stages of L. striatellus. Especially, four genes (LsCGT1, LsSMPD2, LsNAGA1, and LsSMS) and another three genes (LsNAGA1, LsSGPP, and LsSMS) were significantly upregulated in viruliferous third-instar and fourth-instar nymphs, respectively. HPLC-MS/MS results showed that RSV infection increased the levels of various ceramides, such as Cer18:0, Cer20:0, and Cer22:0 species, in third and fourth instar L. striatellus nymphs. Together, these results demonstrate that RSV infection alters the transcript levels of various sphingolipid enzymes and the contents of sphingolipids in L. striatellus, indicating that sphingolipids may be important for RSV infection or replication in L. striatellus.
- Selection and Suitability of an Artificial Diet for Tuta absoluta
Authors: Bajonero JG; Parra JP.
Abstract: Tuta absoluta (Meyrick, 1917) is a key tomato pest in South America and, recently, in Europe and Africa. To develop efficient control methods for this pest, adequate rearing protocols are desirable. As an alternative to tomato leaves (natural diet), we evaluated four artificial diets. Biological traits including larval and pupal viability and development time, pupal weight and deformations were assessed. Additionally, the optimum container size and larval density were evaluated. The diet based on casein, wheat germ and cellulose allowed the best development of T. absoluta, showing higher viability and no negative effects on larval instars and pupal weight. The best container was a glass tube measuring Ø 1 × h 6 cm, topped with waterproof cotton, with a density of three larvae. To evaluate the suitability of this diet, T. absoluta was reared during eight generations and life-table parameters were estimated for the F1, F3, F6, and F8 generations. The total viability (egg–adult) increased over the generations, reaching 75% in the eighth generation. Based on life-table estimations no differences among generations were found. The net reproductive rate (Ro) was higher than 40, the intrinsic rate of increase (rm) ranged between 0.08 and 0.11, the finite rate of increase (λ) was 1.1, the mean generation time (T) have a maximum of 44 d and doubling time ranged from 5.89–8.32 generations. These results indicated that a diet based on casein, wheat germ and cellulose was suitable for T. absoluta rearing in laboratory conditions.
- Spatial and Temporal Distribution of Imidacloprid Within the Crown of
Authors: Turcotte RM; Lagalante A, Jones J, et al.
Abstract: Systemic imidacloprid is the most widely used insecticide to control the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), an exotic pest of eastern hemlock, Tsuga canadensis (L.) Carriére in the United States. This study was conducted to 1) determine the effect of treatment timing (spring vs. fall) and application method (trunk injection vs. soil injection) on the spatial and temporal distribution of imidacloprid within the crown of A. tsugae-free eastern hemlock using a competitive enzyme-linked immunosorbent assay (ELISA), 2) compare ELISA to gas chromatography-mass spectrometry (GC/MS) for the detection of imidacloprid in xylem fluid, and 3) determine the concentration of imidacloprid in leaf tissue using high performance liquid chromatography with tandem mass spectrometric (LC/MS/MS) detection methods. Xylem fluid concentrations of imidacloprid were found to be significantly higher for spring applications than for fall applications and for trunk injections than soil injections in the first year posttreatment. A total of 69% of samples analyzed by ELISA gave 1.8 times higher concentrations of imidacloprid than those found by GC/MS, leading to evidence of a matrix effect and overestimation of imidacloprid in xylem fluid by ELISA. A comparison of the presence of imidacloprid with xylem fluid and in leaf tissue on the same branch showed significant differences, suggesting that imidacloprid moved intermittently within the crown of eastern hemlock.
- Structural and Mechanical Properties of Cocoons of Antherina suraka
(Saturniidae, Lepidoptera), an Endemic Species Used for Silk Production in
Authors: Randrianandrasana M; Wu W, Carney DA, et al.
Abstract: Antherina suraka Boisduval (Saturniidae, Lepidoptera) produces a silken cocoon that has been the focus of efforts to create a commercial wild silk industry in Madagascar. In this study, structural and mechanical properties of the cocoon of A. suraka from two sites were measured and compared to the cocoon of Bombyx mori L. (Bombycidae, Lepidoptera) the world's most common source for silk. Results of environmental scanning electron microscopy and mechanical testing showed that the silk sheet of A. suraka cocoon is less compact, with greater thickness and lower tensile strength and stiffness than that of B. mori. Confirming these results, stiffness and cell and thread density were found to be negatively correlated with thickness, and the cell and thread volumes were positively correlated with thickness. Antherina suraka showed no major differences between silk sheets from Kirindy and Isalo sites in either structural or mechanical properties, except for mean cell volume, which was greater in cocoons from Kirindy. Comparison between the two layers forming the cocoon showed that the inner layer has greater elastic modulus, denser silk distribution and lower porosity. Cocoons from both Kirindy and Isalo are suitable for sericulture. Although the inner layer of cocoon silk is of higher quality than the outer layer, the fact that both layers are of great but lower tensile strength than B. mori silk suggests that the current practice of sewing the two layers together for making one single layer fabric should be continued in efforts to produce a commercially viable product.
- The Genetic Basis of Natural Variation in Drosophila (Diptera:
Drosophilidae) Virgin Egg Retention
Authors: Akhund-Zade J; Bergland AO, Crowe SO, et al.
Abstract: Drosophila melanogaster is able to thrive in harsh northern climates through adaptations in life-history traits and physiological mechanisms that allow for survival through the winter. We examined the genetic basis of natural variation in one such trait, female virgin egg retention, which was previously shown to vary clinally and seasonally. To further our understanding of the genetic basis and evolution of virgin egg retention, we performed a genome-wide association study (GWAS) using the previously sequenced Drosophila Genetic Reference Panel (DGRP) mapping population. We found 29 single nucleotide polymorphisms (SNPs) associated with virgin egg retention and assayed 6 available mutant lines, each harboring a mutation in a candidate gene, for effects on egg retention time. We found that four out of the six mutant lines had defects in egg retention time as compared with the respective controls: mun, T48, Mes-4, and Klp67A. Surprisingly, none of these genes has a recognized role in ovulation control, but three of the four genes have known effects on fertility or have high expression in the ovaries. We also found that the SNP set associated with egg retention time was enriched for clinal SNPs. The majority of clinal SNPs had alleles associated with longer egg retention present at higher frequencies in higher latitudes. Our results support previous studies that show higher frequency of long retention times at higher latitude, providing evidence for the adaptive value of virgin egg-retention.
- Vinasse and Its Influence on Ant (Hymenoptera: Formicidae) Communities in
Authors: Saad LP; Souza-Campana DR, Bueno OC, et al.
Abstract: Sugarcane is an important crop within the Brazilian socioeconomic landscape. There is a constant need for approaches to increase sustainability at all steps of the production chain. Irrigating sugarcane crops with vinasse is one of these approaches, because vinasse is a residue of sugarcane processing that can be used to fertilize these same crops. However, due to its chemical properties, vinasse may be harmful to soil fauna. Analyzing the structure and functional organization of ant communities is a fast and practical way to monitor sites affected by the addition of chemicals. This study compared the structure of soil ant communities in vinasse-irrigated sugarcane crops to those in secondary forests adjacent to the crops. In total, 32 genera and 107 species of ants were observed; of these, 30 species foraged in crop fields and 102 foraged in forests. Twenty-five percent of the species were present in both crops and forests. Ant communities in crop soil had poorer taxonomic composition and lower richness in each functional group compared to communities in forest remnants. However, regardless of vegetation type, epigeic ants were more diverse, and Dorymyrmex brunneus (crop) and Pachycondyla striata (forest) were very frequent. Vinasse did not increase the diversity of epigeic and hypogeic ants, but it may affect the community composition.
- Reviewers for Journal of Insect Science (September 2015–September
Abstract: The Editor-in-Chief and the Subject Editors of Journal of Insect Science thank the following scientists for their voluntary commitment of valuable professional time and expertise to peer reviewing manuscripts submitted for publication in our journal. The quality and scientific stature of the journal depends on the conscientious efforts of these individuals.
- Seasonality of the Mediterranean Fruit Fly (Diptera: Tephritidae) on
Terceira and Sao Jorge Islands, Azores, Portugal
Authors: Pimentel RR; Lopes DH, Mexia AM, et al.
Abstract: Population dynamics studies are very important for any area-wide control program as they provide detailed knowledge about the relationship of Medfly [Ceratitis capitata (Wiedemann)] life cycle with host availability and abundance. The main goal of this study is to analyse seasonality of C. capitata in Terceira and Sao Jorge Islands (Azores archipelago) using field and laboratory data collected during (2010–2014) CABMEDMAC (MAC/3/A163) project. The results from Sao Jorge Island indicate significantly lower male/female ratio than on Terceira Island. This is an important finding specially regarding when stablishing the scenario parameters for a sterile insect technique application in each island. The population dynamics of C. capitata are generally linked with host fruit availability and abundance. However, on Terceira Island fruit infestation levels are not synchronized with the trap counts. For example, there was Medfly infestations in some fruits [e.g., Solanum mauritianum (Scop.)] while in the nearby traps there were no captures at the same time. From this perspective, it is important to denote the importance of wild invasive plants, on the population dynamics of C. capitata, as well important to consider the possibility of having different densities of traps according to the characteristics of each area in order to improve the network of traps surveillance’s sensitivity on Terceira Island.