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The distribution of chemicals on protected crops can be critical for the operators who are forced to make frequent treatments in an enclosed environment and in the presence of high pesticide concentrations. The introduction of organic farming techniques limits these aspects but generally requires a substantial commitment of manpower for the release of beneficial organisms resulting in high costs. To evaluate the feasibility of improving the mechanical application of beneficial organisms a mechanical blower was used. The device was previously tested in the laboratory in terms of mites survival, reproduction and distribution patterns. The application of Phytoseiulus persimilis Athias-Henriot and Amblyseius swirskii Athias-Henriot against Tetranychus urticae Koch and Frankliniella occidentalis (Pergande) on protected crops was investigated. Different application methods of the antagonists were considered: i) hand-sprinkling, ii) separate mechanical release, iii) combined mechanical release, iv) paper sachets (Swirskii- Breeding-System). Compared to hand application the mechanical release allowed a significant reduction in time needed for the distribution, while showing equal pest control effectiveness. P. persimilis was able to control T. urticae adequately in all treatments, while in the case of A. swirskii release a final spinosad application became necessary to provide effective F. occidentalis control. [ABSTRACT FROM AUTHOR]

Rhyzobius lophanthae Blaisdell (Coleoptera Coccinellidae) is a coccidophagous predator known as a natural enemy of Diaspididae scales. This study aimed to determine the suitability of Chrysomphalus dictyospermi Morgan (Hemiptera Diaspididae) as prey for this predator. Several traits such as larval development and survival, reproductive performance and reproductive investment were assessed. Pre-imaginal development time was short whereas immature age-specific survival rate was high. Fecundity, expressed in terms of lifetime fecundity and oviposition rate, was high. The soma and gonads fat contents of females were estimated to be 86.67 ± 1.52 and 13.33 ± 1.52%, respectively. Reproductive effort, the total egg mass expressed as a proportion of the female initial fresh mass, were almost 9-fold of their mass in eggs. Overall, our results show that C. dictyospermi is an essential and highly suitable prey for R. lophanthae and allows a better performance than other prey species used in previous studies. [ABSTRACT FROM AUTHOR]

Squash bug, Anasa tristis DeGeer (Hemiptera: Coreidae), is a major pest of squash and pumpkins in the United States. In order to better understand the importance of natural egg parasitism of this species in Virginia, we conducted a 2-yr statewide survey. In total, 1,127 squash bug egg masses (~20,000 total eggs) were sampled from squash and pumpkins from 43 counties in Virginia from 2014 to 2015. Egg masses were brought back to the lab to record levels of squash bug nymphal emergence or adult parasitoid eclosion and identification. Over 50% of the total squash bug eggs collected statewide were parasitized. Gryon pennsylvanicum Ashmead (Hymenoptera: Scelionidae) was the predominant egg parasitoid accounting for over 98% of all parasitoid adults recovered. The only other species emerging from squash bug eggs was Anastatus reduvii Howard (Hymenoptera: Eupelmidae), which is a generalist parasitoid. G. pennsylvanicum was found in 75% of the counties surveyed with the highest levels of parasitism occurring in the Northern, Southwestern Mountain, and Western Piedmont regions of the state and the lowest levels of parasitism occurring in the Tidewater region in the southeastern portion of the state. Based on this 2-yr survey, G. pennsylvanicum was determined to be a major natural enemy of squash bug, significantly reducing the number of nymphs that emerge from deposited eggs. Conservation of this natural enemy should therefore be a priority for integrated pest management programs in cucurbits. [ABSTRACT FROM AUTHOR]

The objective of the current study was to determine the insecticidal effectiveness of diatomaceous earth formulation (DE) Paya®. The effects of grain commodity (wheat, barley, maize and rice), exposure times and dose rates were evaluated. The efficacy of diatomaceous earth (DE) against 1–7 days old adults of Tribolium castaneum (Herbst) was evaluated on wheat, rice, maize and barley at 26±1°C and 60±5% RH in darkness. The mortality of adults was tested at five concentrations: 0.125, 0.25, 0.5, 1 and 1.5 g/kg of grain and different exposure times (24, 48 h, 7 and 14 d). To evaluate the progeny production, dead and alive adults were removed from containers after 14 days and these containers were kept at above-mentioned conditions for 45 days. The results obtained indicated that the highest adult mortality was observed after the longest exposure period on barley and wheat so that the two highest DE dosages caused 100% mortality of T. castaneum. The efficacy of Paya®on maize and rice was not satisfactory, given that after a 14 days exposure at the highest dose rate the mortality did not exceed 37% and 66% in the case of maize and rice, respectively. The results demonstrated that the mortality increased with rises in concentration and exposure time and also highly affected by grain type. [ABSTRACT FROM AUTHOR]

The flight activity of Coleomegilla maculata DeGeer and Hippodamia convergens Guerin-Meneville (Coleoptera: Coccinellidae) was examined by observing tethered beetles in the laboratory. C. maculata were fed eggs of Ephestia kuehniella Zeller, as were larval H. convergens, whereas adult H. convergens were fed Melanaphis sacchari (Zehntner) to induce egg maturation; adults of both species received water and diluted honey. A spot of magnetic paint was applied to one elytrum of each beetle, which then adhered to a small neodymium magnet attached to a thread. Beetles were permitted 1 h flight opportunities daily for 3-d periods, first as virgins on their fifth day of adult life, secondly after mating, thirdly after females began oviposition, and fourthly after prey were withheld and egg maturation and oviposition ceased. Both species exhibited low flight activity as virgins, and whereas C. maculata females increased their activity after mating, H. convergens females did not. Flight activity in C. maculata did not change with onset of oviposition, whereas it increased in H. convergens males, but not females. In contrast, H. convergens females increased their flight activity after cessation of oviposition, whereas C. maculata females did not. Female flight activity when either virgin or mated correlated weakly with fecundity in C. maculata, but not in H. convergens. Species differences are discussed in the context of nutritional ecology; H. convergens usually enters diapause immediately following emergence, and is more dependent on aphids for reproduction, whereas C. maculata develops and reproduces on a wider range of foods and is not so constrained. [ABSTRACT FROM AUTHOR]

Mating in arthropods is costly and has negative effects on survival. Such effects are often more strongly expressed when individuals are simultaneously exposed to other stress sources. Consequently, the behaviour of virgin and mated individuals often differs. Mated females, for example, search for suitable oviposition sites, whereas virgin females search more for mates. In the present study, we examine the effect of mating separately for females and males on four key behaviours of the red flour beetles: movement activity, movement along the edges of an arena, latency to emerge from shelter and preference for dark microhabitat. After mating, both sexes increase their activity at the same time as moving less along the arena edge, leading to a change in movement pattern. Females possibly change their movement pattern to locate suitable oviposition sites, whereas males perhaps do so to detect additional females with which to mate. Latency to emerge from shelter and dark preference are not influenced by mating, although they increase when measured again after 1 week. Of these behaviours, only movement activity is consistent at the individual level. We also examine whether mating incurs a cost as expressed in the time required to recover from a chill-coma. The latter is a common proxy of cold tolerance in ectotherms. By contrast to our prediction, mating has no effect on chill-coma recovery time, suggesting that either a single mating event does not incur sufficient stress or that there is possibly no trade-off between the energetic cost of mating and of cold tolerance. [ABSTRACT FROM AUTHOR]

Tetranychus urticae Koch (Acari: Tetranychidae) causes severe damage in both greenhouse and field crops. Previous studies have found that a phytoseiid predatory mite, Phytoseiulus persimilis Athias-Henriot, and an entomopathogenic fungus, Beauveria bassiana (Balsamo) Vuillemin, are both potential candidates for the control of this pest and have shown varying degrees of success. We assessed the compatibility of these two biological control agents for control of T. urticae on potted bean plants, examining the following treatments: i) a low release rate of P. persimilis (10 prey:1 predator), ii) a high release rate of P. persimilis (5:1), iii) a single application of B. bassiana (1 × 108 spore/ml), iv) a single application of B. bassiana after application of the low release rate of P. persimilis, and v) a non-treatment control (no application of either B. bassiana or P. persimilis). A single application of B. bassiana reduced the egg and adult populations of T. urticae initially, but mite populations rebounded again after few days. Phytoseiulus persimilis at the high release rate eliminated the pest population completely, while the low release rate failed to control spider mites. The combined application of B. bassiana and low release rate of P. persimilis also successfully controlled T. urticae population ( p < 0.001), with lowest corrected leaf damage (1.5%). [ABSTRACT FROM AUTHOR]

Among environmental factors, temperature has a direct and crucial influence on the key life processes of survival, development, reproduction, and movement of poikilothermic animals and hence their population dynamics. The lower and upper temperature thresholds and optimal temperature have ramifications for all major life processes, where within a specific range, a temperature change results in a proportional rise or fall of the rate of any given process. There are some basic approaches for modeling development response to temperature in arthropods. The oldest and most widely used model is a simple linear description of arthropod development in relation to temperature. The linear model forms the basis of the well-known thermal summation or degree-day (DD) approach to timing prediction. The second approach for predicting arthropod development rate is nonlinear mathematical models. However, given the fundamental role of thermal models in forecasting and integrated pest management programs, the main purpose of this paper was to facilitate the use of thermal models to estimate the developmental response of arthropods to temperature and select the appropriate model with a view to goodness-of-fit and generalizability by designing a user-friendly software. In this paper, the linear and most common nonlinear thermal models and the main criteria for selecting appropriate models are also reviewed. [ABSTRACT FROM AUTHOR]

Investigations were undertaken to clarify the biology of green lacewing Mallada boninensis on its hosts Helopeltis theivora and Oligonychus coffeae, which are two major arthropod pests of tea crop and on an artificial diet. No significant variations were recorded in terms of preoviposition period, oviposition period, oviposition rate, total eggs, hatching success, larval survival and adult emergence when M. boninensis was reared on both hosts. However, all larval instars and pupal development time, as well as adult longevity, were significantly shorter when M. boninesis was reared on H. theivora., We also provide the first report on the predatory potential of M. boninensis against H. theivora. The feeding efficiency of M. boninensis increased with the advancement of each developmental stage. The third-instar larvae of M. boninensis consumed more H. theivora individuals (28.4 ± 1.50) than the first (7 ± 1.11) and second (24.2 ± 1.81) instars over its entire duration., The artificial diet produced significantly superior results in terms of fecundity, hatching success, larval survival and adult emergence when M. boninensis was reared on it compared with when it was reared on H. theivora and O. coffeae., The findings of the present study indicate that M. boninensis can be effectively utilized in integrated pest management programmes for controlling some major arthropod pests of tea by suitably mass rearing them followed by augmentative release. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The anthocorid bug Orius albidipennis Reuter is a generalist predator that feeds on the whitefly Bemisia tabaci Gennadius and the strawberry spider mite Tetranychus turkestani Ugarov & Nikolski in greenhouse crops. There are no previous studies on the potential efficacy of the predatory bug against these pests on greenhouse crops. We report on the efficacy and the prey preference of the predator to control these pests on different host plants under laboratory conditions. In a laboratory experiment, we estimated the predation rates of O. albidipennis at different densities of each prey after 24 h on cucumber and sweet pepper leaves. Predation rates of the predatory bug to T. turkestani and B. tabaci were significantly higher on sweet pepper leaf than on cucumber leaf. We studied the effect of plant species on prey preference and switching of O. albidipennis to B. tabaci and T. turkestani using Manly's α index values and Murdoch's no-switch line, respectively. Our results show that O. albidipennis prefers T. turkestani to B. tabaci on both host plants but its preference for T. turkestani on sweet pepper is significantly greater than on cucumber. Moreover, on sweet pepper, preference values are completely fitted by Murdoch's no-switch line. The findings suggest that morphological defence traits of plants, such as hairy leaves of cucumber, may effectively change prey preference and reduce predation success of O. albidipennis. [ABSTRACT FROM AUTHOR]

Copyright of Gestión y Ambiente is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Garlic is one of several important vegetable species grown in the Czech Republic. Ditylenchus dipsaci (Kühn, 1857) (Tylenchida: Anguinidae), Aceria tulipae (Keifer, 1938) (Acari: Eriophyidae), Rhizoglyphus echinopus (Fumouze & Robin, 1868) (Acari: Acaridae) and R. robinii Claparède, 1869 (Acari: Acaridae), Suillia lurida (Meigen, 1830) (Diptera: Heleomyzidae) are common pest species found on garlic plants in the Czech Republic. Nowadays Aceria tulipae (Keifer, 1938) is beginning to be considered as the one causing damage. Plodia interpunctella (Hübner, 1813) (Lepidoptera: Pyralidae) and Nemapogon granellus (Linnaeus, 1758) (Lepidoptera: Tineidae) are small moths which are common pests usually found on stored products. Both of these species larvae were found as the uncommon pests of stored garlic in the Czech Republic in January 2016. Until now, their harmfulness on stored garlic has been reported only from Central America. [ABSTRACT FROM AUTHOR]

In egg-laying animals with no post-oviposition parental care, between- or within-patch oviposition site selection can determine offspring survival. However, despite the accumulation of evidence supporting the substantial impact predators have on oviposition site selection, few studies have examined whether oviposition site shift within patches ('micro-oviposition shift') reduces predation risk to offspring. The benefits of prey micro-oviposition shift are underestimated in environments where predators cannot disperse from prey patches. In this study, we examined micro-oviposition shift by the herbivorous mite Tetranychus kanzawai in response to the predatory mite, Neoseiulus womersleyi, by testing its effects on predator patch exploitation in situations where predatory mites were free to disperse from prey patches. Adult T. kanzawai females construct three-dimensional webs on leaf surfaces and usually lay eggs under the webs; however, females that have experienced predation risks, shift oviposition sites onto the webs even in the absence of current predation risks. We compared the predation of eggs on webs deposited by predator-experienced females with those on leaf surfaces. Predatory mites left prey patches with more eggs unpredated when higher proportions of prey eggs were located on webs, and egg survival on webs was much higher than that on leaf surfaces. These results indicate that a micro-oviposition shift by predator-experienced T. kanzawai protects offspring from predation, suggesting adaptive learning and subsociality in this species. Conversely, fecundity and longevity of predator-experienced T. kanzawai females were not reduced compared to those of predator-naïve females; we could not detect any costs associated with the learned micro-oviposition shift. Moreover, the previously experienced predation risks did not promote between-patch dispersal of T. kanzawai females against subsequently encountered predators. Based on these results, the relationships of between-patch oviposition site selection and micro-oviposition shift are discussed. [ABSTRACT FROM AUTHOR]

With a view to improving the establishment of Aphidius gifuensis Ashmead, a potential natural enemy for suppression of aphids on vegetables, the effects of host deprivation and honey feeding before release on the parasitoid's egg load and reproduction were studied under laboratory conditions. Host deprivation significantly affected mummy production and survival rate of female parasitoids. A. gifuensis produced more mummies when exposed to a short period (1 and 2 days) of host deprivation, but when host deprivation lasted for 3 days, their mummy production sharply decreased. Offspring produced by parasitoids that had been deprived of hosts for 2 days were much heavier than those produced by parasitoids deprived of hosts for 1 and 3 days. However, host deprivation did not affect emergence rate or offspring sex ratio; the emergence rate was always above 80%, and the offspring sex ratio was always female biased irrespective of whether the host-deprivation period was 1, 2, or 3 days. Honey feeding greatly increased egg load, longevity and decelerated oosorption of A. gifuensis when hosts were absent, and significantly increased parasitoid mummy production in late age. We discuss the results in the context of augmentative biological control, with the view to understanding how to increase parasitoid performance after they are released. [ABSTRACT FROM AUTHOR]

The parasitoid wasp Cephalonomia tarsalis (Ashmead) (Hymenoptera: Bethylidae) is commonly present in stored product facilities. While beneficial, it does not provide a high degree of biological pest control against its host, the saw-toothed beetle Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). A candidate explanation for poor host population suppression is that adult females interfere with each other's foraging and reproductive behavior. We used simple laboratory microcosms to evaluate such mutual interference in terms of its overall effects on offspring production. We varied the density of the hosts and also the spatial structure of the environment, via the extent of population sub-division and the provision of different substrates. Production of C. tarsalis offspring was positively influenced by host density and by the isolation of females. With incomplete sub-division within microcosms offspring production was, in contrast, low and even zero. The provision of corrugated paper as a substrate enhanced offspring production and partially mitigated the effects of mutual interference. We recommend simple improvements to mass rearing practice and identify promising areas for further behavioral and chemical studies towards a better understanding of the mechanisms of mutual interference. [ABSTRACT FROM AUTHOR]

The squash bug, Anasa tristis (DeGeer) (Hemiptera: Coreidae), is an indigenous pest of squash and other cucurbits. Pesticides can control squash bug populations although many small-scale growers in the Southeast seek alternative methods of management. Cultural control methods, including varying the planting date and farmscaping, are not well understood under southeastern conditions. The goal of farmscaping is to increase natural ecosystem functions to aid in the control of pest populations. In the summers of 2014 and 2015, field plots of squash, separated by a minimum of 150 m were organized in a split-split plot design, with floral resources at the whole-plot level and varied planting date at the subplot level. Data were collected on squash bug abundance and fruit yield (kg), and abundance of potential natural enemies of A. tristis. Plots with added floral resources had fewer squash bug adults than plots without added floral resources in four of eight possible year × site × planting date combinations. Furthermore, the site in 2014 which had a reduction in squash bug adult abundance also had an increase in the abundance of potential enemies, including spiders, ground beetles, and predaceous Hemiptera. There were additional instances when potential natural enemy abundance was greater in resourceenhanced plots, but they were not associated with sites that had a reduction in yield loss or squash bug abundance. The use of floral resources to attract natural enemies and beneficial insects merits further investigation. [ABSTRACT FROM AUTHOR]

The different life cycles of aphid species make these organisms good models for studying the short-term consequences of sex. The bird cherry-oat aphid Rhopalosiphum padi has a wide geographic distribution and correspondingly different life cycles. In this study, the life cycles of R. padi collected from six different regions in China were characterized experimentally by comparing the responses of holocyclic and anholocyclic populations to low-temperature and short-photoperiod induction. Clones collected from Chuzhou, Taian, and Taigu consistently reproduced via obligate parthenogenesis, whereas clones from Hami and Baicheng were holocyclic in their response, and those from Lanzhou were both holocyclic and anholocyclic. Prolonged exposure to low temperature and a short photoperiod ( LS) had negative effects on the offspring of anholocyclic aphids with regard to adult lifespan, total longevity, and fecundity compared with aphids maintained at a normal temperature and a long photoperiod ( NL). Holocyclic LS R. padi had longer developmental times at all nymph stages, a shorter adult lifespan, shorter total longevity, and a lower fecundity than NL counterparts. The adult prereproduction period of gynoparae was significantly longer than that of virginoparae, and the total longevity of gynoparae was significantly shorter than that of virginoparae. Moreover, the net reproductive and gross reproduction rates, as well as the total fecundity, were roughly fivefold higher in virginoparae than in gynoparae, indicating that there is the short-term cost of sex. When maintained on their secondary host ( Triticum aestivum), gynoparae, males, and oviparae produced by holocyclic populations could survive, and gynoparae produced oviparae. However, under NL conditions, oviparae could not produce overwintering eggs on the secondary host, whereas a few overwintering eggs were generated by oviparae under LS conditions. Taken together, these results illuminate the complexity of insect responses and contribute to a complete understanding of the aphid life cycle and its evolution. [ABSTRACT FROM AUTHOR]

Flupyradifurone and sulfoxaflor present novel insecticide chemistries with particular efficacy against aphids, and the recent emergence of sugarcane aphid, Melanaphis sacchari (Zehntner), as a pest of sorghum in the United States has resulted in their widespread use. We examined their toxicity to Hippodamia convergens Guerin-Meneville, an important aphid biocontrol agent. We exposed beetles to topical applications of the field rate (FR) of these insecticides, fed them contaminated food (eggs of Ephestia kuehniella Zeller), and gave firstinstar larvae 24-h exposures to leaf residues. More than half of fourth-instar larvae receiving topical applications of sulfoxaflor at FR survived, whereas flupyradifurone at 0.1× FR caused 90% mortality. Adults survived topical treatments better than larvae and without measurable mortality, except flupyradifurone at FR, which killed more than 80% of beetles. Survivors of all treatments had fertility similar to controls, whether treated as larvae or adults. Ingestion of contaminated food caused significant mortality in all treatments (15-40% for adults and 55-85% for larvae), with no significant differences between insecticides at FR. Leaf residues of sulfoxaflor at 1.0 and 2.0× FR caused approximately 60 and 80% mortality of first instars, respectively, whereas flupyradifurone at 0.1 and 1.0× FR caused>90% mortality. Although sulfoxaflor was less toxic to H. convergens than flupyradifurone, the tested FR of flupyradifurone has now been reduced by half. We conclude that neither insecticide appears as toxic as other nicotinic acetylcholine receptor agonists, and that both materials are compatible with integrated pest management programs for M. sacchari. [ABSTRACT FROM AUTHOR]

Recent research in Ghana has demonstrated the effectiveness of an isolate ofB. bassiana,sensu lato(IMI 389521) from the U.K. against the larger grain borerProstephanus truncatus(Horn) (Coleoptera: Bostrichidae), a major pest of stored maize. To determine whether this isolate is effective on immature stages ofP. truncatus, a laboratory study of the response of immature stages (egg, larvae and pupae) ofP. truncatusin maize grains to two concentrations (1 × 109and 3.16 × 109 cfu/kg maize) ofB. bassiana, IMI 389521 formulated with Entostat™ and kaolinite was undertaken. Adult emergence, per cent survival of adults that emerged and the number of larvae in each immature stage were assessed after 45 days. Apart from the egg experiment, higher numbers of adults emerged in grains containing larvae and pupae treated withB.bassianaproduct compared to the untreated maize control. This notwithstanding, survival of emerged adults ofP.truncatuswas greatly reduced inB. bassianatreatments (<10%) compared with 75–95% in the controls. Surface treatment withB. bassianaon pre-infested maize showed a significant effect on the developmental biology ofP. truncatusin Ghana. [ABSTRACT FROM AUTHOR]

The influence of three host plants, namely cucumber, tomato and eggplant, on functional response of male, virgin and mated female predatory bugNesidiocoris tenuiswas investigated on different densities ofTrialeurodes vaporariorumnymphs. The 24-h experiment conducted at laboratory conditions revealed thatN. tenuisexhibited a type II functional response toT. vaporariorumon host plants. There were no significant differences between attack rates, as well as handling times estimated for each adult stage of the predator between host plants. However, on each host plant, the handling time estimated for the mated female in comparison with two other adult stages had lower values (0.7952, 0.6827 and 0.8884 h−1on cucumber, tomato and eggplant, respectively). Handling time estimated for the mated female on cucumber was significantly lower than that estimated for the male predator. The highest maximum handling rate (T/Th) was estimated for the mated female followed by the virgin female and male on all host plants. For three adult stages of the predator, the highest value of this parameter was determined on tomato followed by cucumber and eggplant. Unlike virgin and mated females, the host plant significantly affected prey consumption by the male. Prey consumed by mated females was higher than those obtained for two other adult stages of the predator on each host plant. The difference in trichome density between three host plants may be responsible for the obtained results. These results revealed thatN. tenuisis more effective in the biological control ofT. vaporariorumon tomato in comparison with cucumber and eggplant. [ABSTRACT FROM AUTHOR]

The Box tree pyralid,Cydalima perspectalisWalker (Lepidoptera: Crambidae), is an invasive species in Europe, not yet regulated by natural enemies. It is highly destructive to ornamental and nativeBuxusdue to defoliation by larval feeding. The ability of eightTrichogrammaspecies (T. brassicaeBezdenko,T. bourarachaePintureau & Babault,T. cacoeciaeMarchal,T. cordubensisVargas & Cabello,T. dendrolimiMatsumura,T. evanescensWestwood,T. nerudaiPintureau & Gerding andT. pintoiVoegele) to parasitise and locate eggs ofC. perspectaliswas assessed in the laboratory. In direct observation tests, all species started to examine and oviposit into exposed eggs. Resulting egg parasitism was low and ranged between 4% and 20% for most of the parasitoid species after three days of exposure. OnlyT. dendrolimiparasitised significantly more host eggs with parasitism rates above 40%. On average, two to three progeny emerged from one host egg and the resulting sex ratio was female-biased, indicating suitability of the target host for progeny production. In subsequent cage tests on pottedBuxusplants, againT. dendrolimiwas the most efficient species in locating host eggs on foliage. We conclude thatC. perspectaliseggs are attractive to variousTrichogrammaspecies.T. pintoihad the highest number of egg encounters and active females.T. dendrolimifemales were most able to locate host eggs and to oviposit and produce successfully on them. Nonetheless, further study is needed to clarify the suspected role of potentially egg defensive mechanisms that may impede higher parasitisation inC. perspectalis. [ABSTRACT FROM AUTHOR]

Stimulating the regulation of pests by their natural enemies is a way to improve the sustainability of agriculture and respect for the environment. However, the presence of natural enemies does not guarantee the existence of a pest control service. To what extent are predatory mites commonly found in henhouses actually able to regulate a major egg industry pest mite, Dermanyssus gallinae? To answer this question, we have experimentally recreated portions of a poultry house ecosystem allowing the development of the pest over several generations in the presence of a chick and detritivorous mites (Astigmata) that are ubiquitous and abundant in layer farms. In these conditions, we compared the growth of D. gallinae populations in the presence and absence of native predatory arthropods. No effect of native predators on the growth of the D. gallinae population could be detected despite high initial predator-to-prey ratios and satisfactory growth of predator populations. Prey switching to the alternative prey Astigmata likely dilutes the effect of predation on the target prey. Further exploration is needed to see whether action could be taken to enhance the effect of top-down regulation., (© 2021 Wiley Periodicals LLC.)

Classical biological control is a pest control tool involving the release of imported natural enemies. The Sterile Insect Technique (SIT) comprises releasing sexually sterile insects of a pest into the wild population for suppression or eradication. Both these approaches are environmentally friendly and their combination can result in a synergistic impact on pest populations and improve eradication. However, stringent regulation surrounding the introduction of biological control agents limits their use in eradication owing to the perceived risk of effects on non-target organisms. We investigated the irradiation biology of the egg parasitoid Trissolcus basalis to ascertain whether sterile parasitoids could mitigate the risk of potential sustained non-target impacts. Mated female T. basalis were gamma-irradiated at doses between 120 and 150 Gy and exposed to egg masses of their host Nezara viridula throughout their lifespans. This resulted in host mortality, despite a substantial reduction in developing parasitoid offspring, which followed a negative dose-response. There was no emergence of parasitoid offspring at 140 Gy and above. Irradiation did not affect oviposition behaviour but caused an increase in longevity. Consequently, sterile parasitoids could possibly alleviate concerns regarding the irreversibility of biological control release, which promotes further investigation of their potential role in eradication.

Plants attacked by insects and mites release blends of herbivore-induced plant volatiles (HIPVs), which act as chemical cues that attract predators and/or repel herbivores alongside alerting neighbouring plants. The chemical profiles of avocado (Persea americanaMill. Cultivar Hass) shoots infested with the foliar miteOligonychus yothersi(Acari: Tetranychidae) were analysed using a gas chromatograph coupled to a mass spectrometer (GC-MS); the different collections of volatiles were performed under semi-field conditions in summer. Four infestation treatments were applied to the avocado shoots (uninfested plant or control; low, medium and high mite-infestation levels). The chemical profiles collectedin situchanged qualitatively and quantitatively after infestation, increasing the emissions of (Z)-β-ocimene, (E)-β-ocimene,β-linalool,α-farnesene, farnesyl cyanide and methyl salicylate (MeSA) as opposed to those of the uninfested shoots. The amount of HIPVs emitted by the avocado shoots with the highestO. yothersipopulation density (250 ± 10 mites per leaf) were greater than those of the shoots infested with the lower population density (60 ± 10 mites per leaf); to the emissions of (E)-β-ocimene, sesquiterpenes and MeSA at higher amounts even after seventeen days of continuous infestation. Likewise, the emissions of HIPVs increased with each infestation level; also fluctuating between collecting dates, which indicates that environmental conditions maximized or constrained those emissions. In addition, the damaged foliar area increased with higherO. yothersipopulation densities after seventeen days of infestation. These results indicate that higher mite-population densities and continuousO. yothersi-feeding increases the amounts of HIPVs emitted byO. yothersi-infested shoots in summer. [ABSTRACT FROM AUTHOR]

The objective of this research was to study the abundance and prevalence of Brevipalpus phoenicis and its predators on Gerbera jamesonii Bolus and its relation with different weather variables during a one-year study 2015 at Ismailia Governorate, Egypt. The abundance of B. phoenicis life stages was monitored monthly. The effects of mite's infestation on G. jamesonii morphology represented in leaf, flower, bud and flower deformity numbers during spring was considered, in addition to the photosynthetic pigments. Our results revealed great variations in mite population throughout the year. The highest density of B. phoenicis adults, eggs, larvae, nymphs were recorded in January (50.25±6.08), May (71.85±8.57), January (31.40±4.71), July (74.43±8.73), respectively while the minimum density were recorded in October (4.10±0.83), September (10.30±2.09), August (1.95±0.46) and (16.10±2.50), respectively. Three predacious mites: Amblyseius cucumeris, Hemicheyletia wellsina, Tydeus sp. and one predacious insect Scolothrips longicornis were recorded. Negative correlations was recorded between B. phoenicis eggs or larvae with S. longicornis (-0.122, -0.168), respectively. Significant negative correlations were observed between different B. phoenicis life stages, Tydeus sp. and S. longicornis with temperature and relative humidity. There were significant negative or positive correlations between life stages of B. phoenicis and the morphological characteristics of the plant. Highly significant negative correlation was recorded between mite infestation and photosynthetic pigments. In conclusion, G. jamesonii is recorded as a new host for B. phoenicis with a marked deformation in the plant morphology. In addition environmental factors had a great effect on its abundance. [ABSTRACT FROM AUTHOR]

The recent advances in biocontrol of stored-grain insects using formulated and unformulated strains of entomopathogenic fungi (EPF) are reviewed and discussed. Several liquid and dry formulations of EPF strains were developed and used against these insects. However, a literature search revealed lack of any commercially registered product of these formulations. Therefore, in order to achieve an effective control of these insects, the following potential areas of future research have been identified and discussed: (i) screening for new effective strains of EPF, in addition to new effective formulations, (ii) applying the most effective strains and formulations selected in the previous step under storage conditions, (iii) optimising the proportions of ingredients in the selected formulations and (iv) integrating the products of the most effective formulations, after registration and commercialisation, in the integrated pest management programmes of stored-grain insects. Such products would constitute an appropriate alternative control means to synthetic insecticides and fumigants commonly used for control of these insects. The various obstacles pertaining to how the selected EPF products are planned to be used in ‘real world’ in stored-grain protection are also critically discussed. [ABSTRACT FROM AUTHOR]

Prey for predators can fluctuate in abundance and in quality over time requiring predator strategies to cope with food shortage. Coccinellinae are often associated with sap-sucking pests that exhibit high population unpredictability such as aphids and psyllids.Eriopis connexa(Germar) (Coleoptera: Coccinellidae) is a predator with potential for biological control, especially a well-studied population which is resistant to pyrethroids used to control insect defoliators. Both larvae and adultE. connexawere providedad libitumprey and non-prey foods (pollen and honey water solution) at increasing intervals from 1 to 10 days. Neonate larvae ofE. connexarequired eating prey daily to develop into adults. However, non-prey food such as honey water solution did prolong larval and adult survival but neither fulfilled larval development nor adult reproduction. Honey water solution promoted 100% adult survival up to 25 days in the adult stage without prey with oviposition returning after daily feeding on prey. Females subjected to increased feeding intervals over four days reduced oviposition and lived longer, but 10-day feeding intervals correlated with risk to adult survival. These results indicate the importance of non-food sources inE. connexamaintenance and the ability of larvae and adult females to compensate for prey scarcity. [ABSTRACT FROM AUTHOR]

The potential of a dry powder co-formulant, kaolin, to improve the control of storage beetles by the entomopathogenic fungus Beauveria bassiana, isolate IMI389521, was investigated. The response of Oryzaephilus surinamensis adults to the fungus when applied to wheat at 1 × 1010 conidia per kg with and without kaolin at 1.74 g per kg wheat was assessed. Addition of kaolin increased control from 46% to 88% at day 7 and from 81% to 99% at day 14 post-treatment. Following this the dose response of O. surinamensis and Tribolium confusum to both kaolin and the fungus was investigated. Synergistic effects were evident against O. surinamensis at ≥0.96 g of kaolin per kg of wheat when combined with the fungus at all concentrations tested. For T. confusum, adult mortality did not exceed 55%, however, the larvae were extremely susceptible with almost complete suppression of adult emergence at the lowest fungal rate tested even without the addition of kaolin. Finally, the dose response of Sitophilus granarius to the fungus at 15 and 25 °C, with and without kaolin at 1 g per kg of wheat, was examined. Improvements in efficacy were achieved by including kaolin at every fungal rate tested and by increasing the temperature. Kaolin by itself was not effective, only when combined with the fungus was an effect observed, indicating that kaolin was having a synergistic effect on the fungus. [ABSTRACT FROM AUTHOR]

The insect growth regulator methoprene can be mixed into the matrix used to comprise bags and other packaging materials. Different methodologies were utilized to evaluate the efficacy of different types of methoprene-treated packaging towards Tribolium castaneum (Herbst), the red flour beetle, and T. confusum Jacquelin duVal, the confused flour beetle, two common insect species that infest stored products. Tests were conducted by creating arenas in which larvae were exposed on the packaging surface along with a flour food source, and assessments were made on adults emerging from the exposed progeny. Tests were also done by exposing adults, again with a flour food source, removing the adults after one week, and assessing adult emergence of progeny from those parental adults. In tests with larvae exposed on methoprene-treated birdseed bags, the outside surface had more activity compared to the inside surface, especially on T. confusum. In other studies with different types of packaging materials, there was generally 100% inhibition of adult emergence of exposed larvae or of progeny adults when parental adults were exposed on the methoprene-treated packaging. The best technique for evaluation was to expose late-stage larvae as the test life stage. Results show the potential of using methoprene-treated packaging for bagged storage of processed grains and grain products. [ABSTRACT FROM AUTHOR]

Tetranychus urticae Koch and Tetranychus kanzawai Kishida are important pest mites of various crops of economic importance around the world. Prey consumption and functional responses of two species of phytoseiid mites on these two spider mites were evaluated at 25 ± 1°C, 65 ± 10% RH in the artificial climatic chamber with a photoperiod of 16 h light:8 h dark. The functional response of both Neoseiulus species was type II on three immature stages (egg, larva and protonymph) of Tetranychus species. The value of attack rate coefficients (α) of N. californicus to each stage of Tetranychus was greater than N. longispinosus, and the shortest handling time ( Th) was obtained on larvae followed by nymphs and eggs. The maximum attack rate ( T/Th) on eggs, larvae and nymphs of T. urticae was estimated to be 11.87, 37.23 and 26.95 for N. californicus, and 18.43, 28.98 and 20.67 for N. longispinosus; the maximum attack rate ( T/Tf) on eggs, larvae and nymphs of T. kanzawai was estimated to be 11.90, 42.97 and 39.60 for N. californicus, and 24.15, 31.60 and 24.45 for N. longispinosus. When different densities of prey were offered to the predators, more prey was consumed at higher prey densities, and interaction between prey stage and prey density was significant for N. californicus, but not significant for N. longispinosus. The ability of N. californicus preying on larvae and nymphs of both Tetranychus species was significantly greater than N. longispinosus at high prey densities, but N. longispinosus consumed more eggs than N. californicus. [ABSTRACT FROM AUTHOR]

Strawberry, Fragaria ananasa Duchesne, is one of the most favorite fruits throughout the world and its commercial production is highly influenced by available nitrogen (N). Nitrogen improves plant quality but unfortunately also increases its serious pest, Tetranychus urticae Koch. So, life table parameters and population growth rate of two-spotted spider mite (TSSM) were compared with four nitrogen concentrations (namely, 0, 50, 80 and 100% of the recommended N level) on strawberries under greenhouse condition. The 100% nitrogen application resulted in enhancing the protein and decreasing phenol content of the host plants. Also the mite's intrinsic rate of increase ( rm) and the instantaneous rate of increase ( ri) reached their maximum (0.234 and 0.26, respectively). The plants received the 80% and lower N showed a decrease in protein content and higher phenol content causing a significant decrease in TSSM's rm (0.218-0.202) and ri (0.24-0.22). Manipulating the N content in fertilization programs of strawberries as a strategy in integrated pest management is discussed. [ABSTRACT FROM AUTHOR]

Investigations were carried out to assess the spatial flight pattern and movement of three stored grain insect pests in storage godown using sticky traps. Significant variations of Tribolium castaneum (Herbst) trap catches were registered on different height and trapping periods. The traps placed at a height of 18 feet recorded the highest mean trap catches of T. castaneum (341.3 / trap) followed by 15 feet height (202 / trap) and catches between 6 PM - 10 AM were the highest mean trap catches of T. castaneum, which ranged from 73.7 to 341.3. Whereas, 4 PM - 6 PM registered 46.3 to 195.7 numbers per trap. The maximum mean trap catches of Cryptolestes ferrugineus (Stephens) was observed at a height of 3 feet from the ground level and ranged from 1.7 to 12.0 numbers per trap for different trapping period. Among the trapping period, the period between 4PM - 6PM recorded the maximum mean trap catches (12 / trap). There were no significant differences of mean trap catches of Ephestia cautella (Walker) on different height intervals and trapping period. Very low number of E. cautela was trapped throughout the study period and the mean trap catches ranged from 0.3 to 2.0 per trap. The trap placed at a height of 18 feet and late evening hours of 6 PM to 10 AM accounted for the maximum mean trap catches (2.0 / trap). The independent variable temperature exerted a significant influence on movement of T. castaneum and C. ferrugineus and showed that one degree rise in temperature could reduce the trap catches by 3.15 and 4.41 numbers, respectively. However, the relative humidity showed significant influence on movement of T. castaneum and E. cautella and revealed that one per cent of relative humidity could increase the trap catches by 3.29 and 2.99 numbers, respectively. [ABSTRACT FROM AUTHOR]

Laboratory bioassays were carried out to evaluate the insecticidal effect ofBeauveria bassiana(Balsamo) Vuillemin (Ascomycota: Hypocreales) germinated conidia, a commercial formulation of diatomaceous earth and a liquid formulation of spinosad, applied alone or in all possible combinations on wheat, against adults of the confused flour beetle,Tribolium confusumJacquelin du Val (Coleoptera: Tenebrionidae). Diatomaceous earth was applied at one (200 ppm), the fungus at two (100 and 300 ppm) and spinosad at three (0.01, 0.1 and 0.5 ppm) dose rates, whereas all combinations of two or three of the insecticide concentrations were also tested. Insect mortality was determined after 2, 7 and 14 d of exposure. The simultaneous use ofB. bassianagerminated conidia with diatomaceous earth notably increased mortality ofT. confusumadults by sixfold 7 d after exposure, as compared with eitherB. bassianaor diatomaceous earth alone. When diatomaceous earth and spinosad were combined, diatomaceous earth did not increase the efficacy of spinosad. In general, the combination of all three agents did not differ from either the application of the agents tested alone, or their binary combinations, in most treatments examined. [ABSTRACT FROM AUTHOR]

Biological control of Tetranychus urticae relies mainly on specialist predators that are capable of coping with the dense web of spider mites. The role of generalist predators, however, has been less studied. To evaluate the development and predation of immature Neoseiulus cucumeris on Tetranychus urticae eggs, three experiments were conducted in the laboratory at 25 °C. The results showed that only 20-25% N. cucumeris eggs developed into adults when provided with 120 frozen spider mite eggs at the start of the experiment. The rate of predation by predator immatures and their survival increased with prey density. When N. cucumeris were fed 12-24 frozen spider mite eggs every day from larvae, they completed their immature development in 11-14 days and consumed 133-208 spider mite eggs. When the predator was offered 200 fresh spider mite eggs at the start of the experiment, they developed faster when fed every day, with adults emerging in 7 days. It was found that the webbing of spider mite lowered the predation of N. cucumeris. Compared with specialist predators, predation rates by N. cucumeris were much higher. The potential for N. cucumeris to control of T. urticae is discussed. [ABSTRACT FROM AUTHOR]

A greenhouse experiment was conducted to determine the effect of plant spacing and predator–prey ratio on dispersal and foraging efficiency of the predatory mite,Phytoseiulus persimilis, on the twospotted spider mite,Tetranychus urticae. When predators were released at the end of spider mite-infested arrays of lima bean plants that had either no spacing or two different patterns of spacing among plant rows, plant damage was uniformly low throughout the experiment at both predator–prey ratios (1:10 and 3:10) in the treatment with no spacing. In contrast, damage was higher in both treatments where plant rows were interrupted by spacing. At the 1:10 ratio, more plants closer to the predator release point experienced moderate damage than at the 3:10 ratio where only the plant rows farthest from the release point had unacceptable damage. Our findings suggest that point releases ofP. persimilisat the standard 1:10 predator–prey ratio should be effective within a diameter of at least 65 cm on mite-infested patches of plants where pots are touching. However, if gaps in plant rows exist, even large numbers of predators may not be sufficient to protect parts of the crop unless predators are released at shorter fixed points in the greenhouse crop. [ABSTRACT FROM PUBLISHER]

Seasonal changes in egg parasitism and predation rates on sentinel (laboratory-reared) and wild (naturally occurring) egg masses of the squash bug, Anasa tristis (De Geer), were evaluated in squash fields in Maryland from June through September in 2013 and 2014. Rates of egg parasitism were significantly higher on wild egg masses than on sentinel egg masses. Squash bug nymphal emergence was significantly higher on sentinel egg masses than on wild egg masses. Between the first week of July and the first week of September of both survey years, squash bug nymphs emerged from 24.2% of wild eggs compared with 46.2% of sentinel eggs and parasitoids emerged from 55.7% of wild eggs compared with only 21.8% of sentinel eggs. Sentinel egg masses significantly underestimated the rate of natural egg parasitism. The egg parasitoid, Gryon pennsylvanicum (Ashmead), was responsible for over 99% of parasitism of squash bug eggs. There was a significant negative correlation between parasitoid emergence and nymphal emergence, suggesting that parasitoids were able to suppress squash bug populations. The average rate of parasitoid emergence peaked on wild egg masses on the fifth week of July at 72.8%, whereas the average rate of nymphal emergence from wild egg masses was <20% from the fifth week of July until the first week of September. These results demonstrate that G. pennsylvanicum was able to efficiently track wild squash bug eggs throughout the season and that it has the potential to be an effective biological control agent of the squash bug in Maryland. [ABSTRACT FROM AUTHOR]

The oviposition behaviour ofAedes aegyptiand the effectiveness ofMetarhizium anisopliaeconidia formulated in water or oil-in-water againstA. aegyptiadults and eggs were tested in multi-choice and no-choice tests in oviposition devices under laboratory conditions. Both females and males rested in the devices, regardless of the formulation, and were not repelled by the presence of conidia (up to 106 conidia/cm2) without oil or formulated with oil on treated filter paper arranged in the device. However, at higher oil concentrations (≥0.1 μl/cm2), regardless of the presence of conidia, the number of eggs laid by gravid females on the filter paper dropped. The susceptibility of adults, especially of males, to fungal infection increased up to a 15-day incubation. An elevated number of larvae (≥41%) eclosed from eggs laid on the moistened filter paper in the device even without submersion of eggs in water, and these larvae subsequently died. In the laboratory, 1 μl/cm2oil combined with 106 conidia/cm2clearly reduced eclosion to 1.8% after submersion of eggs in water compared to ≥13% eclosion in the control. In field tests in Goiânia, Brazil, eclosion of aedine larvae from eggs laid on filter paper previously treated with oil-in-water formulated conidia dropped to between 0% and 36% compared to 22–50% in the control. Promising results of laboratory and field tests withM. anisopliaeformulated in water or oil-in-water and tested in a device emphasised the effectiveness of a fungus-based formulation for aedine mosquitoes in peridomestic areas. [ABSTRACT FROM AUTHOR]

We evaluated the residual efficacy of four liquid sprays and four ready-to-use aerosols that are commonly used in the U.S. against a field-collected bed bug, Cimex lectularius L., strain with moderate resistance level to pyrethroids. The four liquid sprays were: Tandem (0.1% thiamethoxam, 0.03% lambda-cyhalothrin), Temprid SC (0.05% imidacloprid, 0.025% cyfluthrin), Transport GHP (0.05% acetamiprid, 0.06% bifenthrin), and Demand CS (0.03% lambda-cyhalothrin). The four aerosols were: Alpine (0.5% dinotefuran), Bedlam (0.4% sumithrin, 1.6% MGK 264), Bedlam Plus (0.4% sumithrin, 1% MGK 264, 0.05% imidacloprid), and Phantom (0.5% chlorfenapyr). Bed bugs were confined for 4 h to treated substrates (aged 24 h). Four substrates were tested: fabric, unpainted wood, painted wood, and vinyl. Bedlam, Demand CS, and Temprid SC resulted in ≤70% mortality on all tested substrates. Among the other five products, substrate type significantly affected their residual efficacy, except for Transport GHP, which caused ≥89.7% mortality regardless of the substrate. The effect of exposure time (5 min, 4 h, and 24 h) on the efficacy of Transport GHP and Phantom aerosol also was evaluated. A 4 h continuous exposure to Phantom aerosol or Transport GHP residue caused similar mortality to 24 h exposure and higher mortality than 5 min exposure. [ABSTRACT FROM AUTHOR]

Plants frequently engage in simultaneous interactions with diverse classes of biotic antagonists. Differential induction of plant defence pathways by these antagonists, and interactions between pathways, can have important ecological implications; however, these effects are currently not well understood. We explored how Tomato yellow leaf curl virus (TYLCV) influenced the performance of its vector ( Bemisia tabaci) and a non-vector herbivore ( Tetranychus urticae) occurring separately or together on tomato plants ( Solanum lycopersicum). TYLCV enhanced the performance of B. tabaci, although this effect was statistically significant only in the absence of T. urticae, which adversely affected B. tabaci performance regardless of infection status. In contrast, the performance of T. urticae was enhanced (only) by the combined presence of TYLCV and B. tabaci. Analyses of phytohormone levels and defence gene expression in wild-type tomatoes and various plant-defence mutants indicate that the enhancement of herbivore performance (for each species) entails the disruption of downstream defences in the jasmonic acid (JA) pathway. For T. urticae, this disruption appears to involve antagonistic effects of salicylic acid (SA), which is cumulatively induced to high levels by B. tabaci and TYLCV. In contrast, TYLCV was found to suppress JA-mediated responses to B. tabaci via mechanisms independent of SA. [ABSTRACT FROM AUTHOR]

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The performance of four aphid predators, Hippodamia convergens Guerin-Meneville, Coleomegilla maculata DeGeer, Chrysoperla carnea Stephens and Orius insidiosus Say was compared on three prey species: Schizaphis graminum Rondani, Melanaphis sacchari (Zehntner), and Ephestia kuehniella Zeller eggs. Species predatory in both life stages (all except Ch. carnea) were reared on E. kuehniella eggs and switched to aphid prey for assessment of reproduction. Differences were greater between the E. kuehniella and aphid diets than between the two aphid species. Juvenile survival was high for all predators on all prey, except for O. insidiosus, which had survival on E. kuehniella> S. graminum>M. sacchari. The fastest development of Ch. carnea and O. insidiosus was obtained on E. kuehniella, whereas H. convergens developed fastest on S. graminum, and C. maculata did not differ among diets. S. graminum also yielded the largest H. convergens adults, whereas the largest adults of other predators were obtained on E. kuehniella. Female fecundity and egg viability were similarly high on both aphid diets for H. convergens and C. maculata, whereas, on E. kuehniella, 50% of the former entered reproductive diapause and the latter species had reduced fecundity. Reproductive success of Ch. carnea was S. graminum=M. sacchari>E. kuehniella, but it was similar among treatments for O. insidiosus, although female infertility ranged from 25 to 37.5%. We concluded that all the predators studied are preadapted to utilize sugarcane aphid as prey and have excellent potential to provide sustainable biological control of this newly invasive pest. [ABSTRACT FROM AUTHOR]

Rapid evolutionary change in seasonal timing can facilitate ecological speciation and resilience to climate warming. However, the molecular mechanisms behind shifts in animal seasonality are still unclear. Evolved differences in seasonality occur in the European corn borer moth (Ostrinia nubilalis), in which early summer emergence in E-strain adults and later summer emergence in Z-strain adults is explained by a shift in the length of the termination phase of larval diapause. Here, we sample from the developmental time course of diapause in both strains and use transcriptome sequencing to profile regulatory and amino acid changes associated with timing divergence. Within a previously defined quantitative trait locus (QTL), we nominate 48 candidate genes, including several in the insulin signaling and circadian rhythm pathways. Genome-wide transcriptional activity is negligible during the extended Z-strain termination, whereas shorter E-strain termination is characterized by a rapid burst of regulatory changes involved in resumption of the cell cycle, hormone production and stress response. Although gene expression during diapause termination in Ostrinia is similar to that found previously in flies, nominated genes for shifts in timing are species specific. Hence, across distant relatives the evolution of insect seasonality appears to involve unique genetic switches that direct organisms into distinct phases of the diapause pathway through wholesale restructuring of conserved gene regulatory networks. [ABSTRACT FROM AUTHOR]

Wolbachia are endosymbiotic bacteria that are widely distributed in arthropods. The bacteria cause reproductive disorders and affect fitness-related traits of their hosts. The generalist predatory mite Neoseiulus cucumeris(Oudemans) (Acari: Phytoseiidae) is a cosmopolitan species commonly used as a biological control agent for mites. Here we investigated the effect of Wolbachia infection in the prey, Tetranychus urticae, on predation by N. cucumeris by using both functional response tests (effect of prey egg density on predation) and choice and no-choice tests. The rate of egg consumption decreased with increasing egg density for both infected and uninfected eggs (Type II responses). In a no-choice test, N. cucumeris consumed approximately equal numbers of infected and uninfected eggs, nymphs and adults but consumed fewer infected larvae than uninfected larvae. In the first choice test, different developmental stages of T. urticae were provided, N. cucumeris preferred eggs and larvae over nymphs and adults. Furthermore, to determine how pre-infestation, developmental stages of prey and bacterial infection affect the choice of N. cucumeris, the second choice test was performed. N. cucumeris preferred pre-infested leaf discs over leaf discs that had not been infested, and had a significant preference for uninfected prey, regardless of the presence of plant tissue. These results suggest that N. cucumeris is first attracted by volatiles emitted by attacked plants and then select their preferred prey. [ABSTRACT FROM AUTHOR]

The Mediterranean flour moth (Ephestia kuehniella Zeller) is a worldwide pest of stored grains and other grain-based foods. In this research, the insecticidal activity and synergistic effects of the entomopathogenic fungus (Beauvaria bassiana) and three botanical compounds including : essential oils of Artemisia haussknechtii and Citrus vulgaris and extract of Azadirachta indica were tested against third instar larvae of E. kuehniella. All experiments were conducted in laboratory conditions at 28±1°C, 65±5% RH and a photoperiod of 12 : 12 (L : D). Results showed that all the botanical compounds and entomopathogenic fungi exhibited larvicidal activity against E. kuehniella. The LC50 values by probit analysis were 479.13 and 110.98 μl/lair, for essential oils of A. haussknechtii and C. vulgaris, 47502.6 ppm for extract of A. indica and 6.3 × 104 conidia/ml for B. bassiana, respectively. Results showed that the mixture of essential oil of C. vulgaris and B. bassiana fungi had synergistic effect on mortality of E. kuehniella larvae (SR=1.20). [ABSTRACT FROM AUTHOR]

The egg parasitoid Trissolcus vassilievi (Mayr) (Hymenoptera: Scelionidae) is a significant natural enemy of the sunn pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae), the most important pest of wheat in Iran. This study examined the developmental time and egg-to-adult survival of two geographically separate populations of T. vassilievi on two corresponding host populations at five constant temperatures ranging from 15.0 to 35.0±1°C. No wasps of either population emerged at 15.0°C and the temperature threshold for development was similar between populations, ranging from 13.1±0.3 to 13.8±0.4°C for males and 12.2±0.1 to 12.6±0.1°C for females, but the thermal constant varied with gender and parasitoid population. Development of wasps from the colder Tabriz location was slower, with thermal constants for males and females of 172.6±3.1 and 204.1±1.2 degree-days, respectively, compared to Varamin wasps with 164.7±3.0 and 195.6±1.3 degree-days, respectively. Based on genetic inheritance patterns, reciprocal crosses between the two populations were expected to result in females with thermal phenotypes intermediate to their parental populations, and males that resembled their mothers. However, female progeny of crosses more closely resembled their maternal population, indicating a maternal effect on thermal phenotype. Furthermore, the magnitude of the maternal effect on the thermal constant was asymmetric and was more strongly expressed by Varmin than Tabriz females. These results suggest the possibility of using selective crosses between wasp populations, in combination with artificial selection in the laboratory, to tune the thermal phenotype of parasitoids to specific regions prior to augmentative releases. [ABSTRACT FROM AUTHOR]