Search

The use of insecticides in flowering oilseed rape (Brassica napus L.) against pest insects such as the brassica pod midge (Dasineura brassicae W.) often conflicts with the protection of pollinating and beneficial insects. Dasineura brassicae is a major pest insect in European oilseed rape production. However, a comprehensive and sustainable pest control strategy within the framework of integrated pest management (IPM) does not exist, and little research on the insect has been published during the past two decades. This paper reviews the existing knowledge about D. brassicae along its life cycle and is intended to form the basis for further research activities on pod-damaging pest insects in oilseed rape. Important knowledge gaps are identified, regarding the significance of natural enemies, diapause induction, and predictions on damage potential, based on initial pest insect population. The short lifespan of the adults is particularly challenging in praxis. The implementation of IPM for D. brassicae is discussed on the basis of the four IPM steps (set an economic threshold, establish pest monitoring, preventive measures, and direct control measures) and remaining hurdles, as well as potential solutions for a better IPM, are identified. For D. brassicae, there is no science-based economic threshold and no applicable monitoring methods for farmers, which hinders a field-specific damage forecast and the precise timing of insecticide applications. Research into improved monitoring (e.g. selective attractants, real-time monitoring using remote-sensing technologies) appears to be a promising step towards an integrated pest management of D. brassicae.

Application of broad spectrum synthetic insecticides can disrupt the success of beneficial insects along with resurgence of pest because of their toxic effects on biocontrol agents. The sustainable pest management in agro-ecosystem demands parallel assessment of toxic impact of insecticides to target pests and their key biocontrol agents before integrating them with insecticide use in crops. Here sub-lethal effects of profenofos, citrus oil and their mixture at their sub-lethal concentration level (LC25) recorded for citrus mealybug were assessed against adults of Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) and second instar larvae of Chrysoperla carnea Stephen under laboratory conditions through consumption of treated Planococcus citri individuals. Feeding rate significantly reduced when C. montrouzieri and C. carnea were fed separately on mealybug (preys) exposed to sub-lethal concentration of profenofos, citrus oil and their mixture. Maximum prey consumption (33.10 ± 0.8, 16.05 ± 0.30 mealybug numbers) was observed in citrus oil treatment followed by single treatment of profenofos (21.05 ± 0.80, 10.85 ± 0.30) when compared with control (40.15 ± 0.80, 24.85 ± 0.30) (untreated) for C. montrouzieri and C. carnea, respectively after 24 h. Lowest number of P. citri consumption was assessed in mix of profenofos with citrus oil (15.15 ± 0.80, 7.75 ± 0.30) for C. montrouzieri and C. carnea respectively. Mortality of both predators was influenced by ingestion of contaminated mealybug such as least mortality (15%, 35%) was recorded with citrus oil while maximum (25%, 60%) in mixture of profenofos compared to control (10%, 30%) for C. montrouzieri and C. carnea, respectively. Predator preferences behavior also showed avoidance response towards profenofos and its mix with citrus oil as both predators spent maximum time (minutes) on leaves treated with citrus oil followed by profenofos whereas least was observed on mix of profenofos with citrus oil when compared with untreated leaves (control). Citrus oil alone at sub-lethal concentration may be utilized with both C. montrouzieri and C. carnea. From present findings, use profenofos even at sub-lethal concentration should be avoided when C. montrouzieri adult and /or larvae of C. carnea may be used for mealybug suppression.

The extracts obtained from Neem tree (Azadirachta indica) have been worldwide used indigenously as an insect pest antifeedant, and are known to be used by traditional medicine practitioners. The study was undertaken to investigate the impact of the synthetic pesticides and neem plant extracts on pollinators and crop yield of Pigeon Peas (Cajanus Cajan), and usage of the neem extracts on the field for pest management. The plant extracts were obtained in both aqueous and organic solvents. The insect pest infestation was more pronounced on untreated pigeon pea crop field compared to the field treated with neem extract or pesticide Dimethoate field. The field treated with neem plant extracts showed high frequency (abundance) and diversity in the numbers of pollinators of families Megachilidae and Apidae compared to the field treated with the pesticide Dimethoate. The activity of the active extracts was also performed in the dual-choice tests and No-Choice tests at different concentrations. The seed yield was high for neem extract treated field (2774 kg ha−1) than dimethoate treated (1602.8 kg ha−1) and untreated crop (1161.12 kg ha−1). Therefore the finding showed that neem based pest control is more efficient and increased yield production than synthetic pesticides/insecticides treatment. The research findings and observations from this report proved that beneficial insects are not affected or harmed with application of Neem plant extracts, and can continue to perform their valued services even after the application of Neem plant extracts, whereas their numbers decreased significantly on treated plants with synthetic pesticides. This is an indication that the most significant alternative strategies for insect control is the use of botanical pesticides particularly Neem extracts, and may be the most efficient means to replace a wide range of synthetic pesticides. To our knowledge, this is the first study that was done in East Africa specifically in one of the hottest province (Eastern province) of Rwanda, and can help to contribute in plant protection as the use of dimethoate is prohibited in various parts of the word.

The tomato moth, Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae), is one of the most damaging pests of tomato crop in Turkey and is of great economic importance in greenhouse-grown tomatoes. Current control of this pest has heavily relied on the use of synthetic insecticides, inducing the selection of resistant T. absoluta populations and negative environmental impact. In this study, the efficacy of mass trapping using a new-designed light trap (so-called ecosav-D1) in reducing leaf and fruit damages in greenhouse-grown tomatoes was investigated in Antalya (in southwest Turkey). Trials were carried out in commercial plastic greenhouses equipped with insect-proof nets in both autumn–winter and summer–autumn tomato growing seasons in 2019 and 2020. In each season, the study greenhouse was divided into two equal plots using anti-insect net (40 mesh); in one of them, the new-designed light trap was tested at a density of 1 trap/250 m2, and in the other one, conventional control system, based largely on the use of synthetic pesticides, was implemented for comparison. In the light trap plot, total number of adult T. absoluta, other pests and beneficial insects caught per trap was recorded weekly. The efficacy of mass trapping in reducing leaf and fruit damages was evaluated by comparing weekly damage on leaves (number of larval mines on 1 leaf per plant on 50 randomly chosen plants) and percentages of damaged fruits in each harvest date in both plots. Results showed that mass trapping of adult T. absoluta using the new-designed light trap was effective in reducing leaf and fruit damages at low/moderate T. absoluta population density in autumn–winter growing season. Considering the seasonal averages, significantly lower leaf and fruit damages were observed in the light trap plot (3.2 larval mines/leaf/plant and a fruit damage of 13.4%) than in the conventional plot (6.9 mines/leaf/plant and 18.3%, respectively). On the other hand, although the light trap significantly reduced leaf and fruit damages during the summer–autumn growing season, it was partially ineffective when the pest density soared at the end of the tomato cultivation. In both growing periods, higher densities of tomato moth resulting in much more leaf and fruit damages were observed in the conventional plot, compared with the trap plot. Overall results suggest that the new-designed light trap can be an effective tool for the integrated pest management (IPM) of this pest in greenhouse tomato cultivation.

The use of pesticides may pose a serious threat to soil and water quality, human health, food safety, aquatic species and beneficial insects. Biological control is an effective component of integrated pest management comprising importation, augmentation and conservation. Conservation of natural enemies could enhance or limit the efficiency of herbivorous insect pests. The present study was designed to evaluate the efficiency of Diaeretiella rapae (McIntosh) and other food resources impacts on parasitoid’s fecundity, survival and efficiency. The effect of different insecticides [Carbosulfan, Imidacloprid, Diafenthiuron and Lufenuron] was also evaluated in a laboratory controlled experiment. The results revealed that females fed on aphid honeydew proved to be of poor quality as compared to other sugar sources, including honey and sugar solution and has a positive impact of mating on monogenesis. The negative impact was observed on oviposition activity by female reared in the laboratory having less number of mature eggs than females collected in the field. All insecticides demonstrated dose-dependent mortality of D. rapae. In conclusion, food and host availability and insecticides affect the efficiency of D. rapae. These results could lead to the hypothesis that D. rapae females have a high mortality rate in the field due to lower aphid hosts.

There is increasing concern about the toxic effects of chemical pesticides on human health and the environment. Many alternatives, however, are viewed as impracticable or inefficient for agricultural needs. Here, a sustainable, environmentally friendly strategy was designed for the control of major rice insect pests (i.e. Nilaparvata lugens, Cnaphalocrocis medinalis and Chilo suppressalis) with minimal impact on natural enemies via selection of a specific entomopathogenic fungal strain for use as a biological control agent. In large-scale multiyear field applications, Metarhizium anisopliae CQMa421 was shown to act as effectively as chemical pesticides for pest control. Rice pest control applications in all major rice-producing provinces in China covering > 6000 hectares, performed over a period of 8 years (2011–2018), showed equal rice harvest yields between the use of the fungal pathogen versus chemical pesticides. More importantly, the use of the specific fungal pathogen isolated by this strategy resulted in an increase in beneficial insects and other animals. These long-term field evaluation data and large-scale application results demonstrated the feasibility of shifting from chemical dependency to more nuanced approaches for pest control for maintaining agricultural productivity while protecting natural enemies. With this strategy, new specific fungal strains can also be isolated to control the main pests of other crops.

Insect predation problem in agriculture and forestry has challenged researchers worldwide to identify newer eco-friendly insecticides. Among them Bacillus thuringiensis δ-endotoxin (Bt) has been the most widely used commercial insecticide till date. The advantages of Bt as a “green” insecticide are its high specificity to target insects (it is nontoxic to mammals, birds and even to most beneficial insects) and the slow rate of development of resistance against it by insects. This toxin used either in the form of bio formulations or through its expression in crop plants, is found to be sensitive against insect pests belonging to the family Lepidoptera, Coleoptera and Diptera. However, the sap sucking homopteran group of insects generally remain insensitive to Bt toxin and show susceptibility to various plant lectins when fed with artificial diet or through expression in transgenic plants. This review demonstrates the insecticidal potential of some candidate proteins and their possible mode of action by identifying their target molecules in insects’ tissue. We also provide an overview of the applicability of these proteins in crop protection.

Insects provide key ecosystem services such as pollination, dung burial, soil enhancement, and pest control. Global insect decline requires restoration of the plant–insect mutualistic interactions. By using magnet plants, it is possible to supply beneficial insects with better resource availability and create more sustainable habitats. Current management practices recommend using Umbellifers (Apiales, Apiaceae) in restoration projects. However, analyses of the structure and dynamics of entomofauna associated with this plant family is needed to facilitate practical actions. Here the attention is focused on species composition and seasonal dynamics of beneficial insects associated with sweet fennel Foeniculum vulgare (Apiaceae, Umbelliferae) in Crimea. A 2-year sampling campaign identified 60 insect species from 40 genera across 20 families and four orders: Hymenoptera, Diptera, Coleoptera, and Neuroptera. These insects represented the groups such as social wasps, bees, ants, bumble bees, potter wasps, beetles, lacewings, mud daubers, tachinid flies, and hoverflies. Social wasps and hoverflies dominated in sample collections. Most of insects collected benefit ecosystems and provide essential ecosystem services. During fennel’s flowering season, the number of visits by bumble bees, beetles, bees. and wasps decreased. Contrastingly, dipterans visitation increased towards the end of the season. Such trends might be explained with fennel’s functional protandry, bias in nectar production between male and female flower stages, and insects’ feeding preferences. F. vulgare attracts a diverse assemblage of beneficial insects and consequently can be recommended as a magnet species. When aiming to attract specific insect groups, the seasonal dynamics of fennel’s associated entomofauna should be considered.

Beneficial plant–microbe interactions in the rhizosphere have been found to enhance plant growth and development. Arbuscular mycorrhizal fungi (AMF), a major group among these microbes, have been found to improve plant fitness through mycorrhizal symbiosis. Despite being well documented in various natural and domesticated study systems, few studies have examined whether AMF also has cascading effects on other traits, such as influencing insect community dynamics through attraction/repulsion of beneficial and harmful insects. To test this, we planted Sorghum-sudangrass (Sorghum x drummondii), a fast-growing annual grain/forage crop, either inoculated with commercial AMF mix or left as control in lab and field experiments. We hypothesized that AMF would enhance plant growth and influence the recruitment of insect herbivores and their natural enemies due to possible alterations in plant defense pathways. Our results suggest that while AMF-inoculated plants had significantly better germination, growth, and establishment; they also experienced a lower initial incidence of Spodoptera frugiperda, a major herbivore on Sorghum in the Lower Rio Grande Valley. In addition, our insect community trapping experiment revealed that AMF-inoculated plants attracted significantly more beneficial insects (predators and parasitoids) and a lower number of damaging herbivores. Taken together, our field and lab data show that AMF can not only positively influence plant growth traits but can also provide defenses against herbivores by selectively attracting beneficial insects and repelling herbivores, with implications for sustainable pest management strategies.

Creating non-crop habitats for sustaining pollinators and other beneficial insects in agricultural landscapes has gained momentum in recent times. However, in the tropics, considering limited availability of land for non-crop habitat creation, it is critical to select right kind of non-crop plant species with floral traits that can attract pollinators in good number. We tried to understand bees’ preferences with respect to two important visual cues belonging to four common non-crop species (Sida acuta, Stylosanthes hamata, Limnophila repens, Tephrosia purpurea) in the study area. We grew these plants in pots and arranged them in 5 combinations based on flower colour and structure. Increased bee visitation was observed in flowers that had blue petals and in complex flowers (reproductive parts hidden). However, complex structure of the flower rather than petal colour was more important in attracting bees. This information will be crucial in making species choice for creation of non-crop habitats in the limited available spaces in the tropical agricultural landscape.

The results show that the orb-weaver spiders, Neoscona theisi and Cyrtophora citricola, occurred in both guava and citrus agroecosystems, and their prey primarily comprised a wide diversity of insect pests. In contrast, the sheet web-constructing social spider, Stegodyphus sarasinorum, occurred only in the citrus agroecosystem and preyed mainly on the beneficial insects, particularly the pollinators, including the Asian honeybee, Apis cerana, along with the predaceous ladybird beetle, Coccinella septempunctata, damselfly, Agriocnemis femina, and the ant, Camponotus compressus. Field observations revealed that the beneficial insects caught and captured by the social spiders comprised mainly the flower-visiting insects of ornamental and weed plants growing in the vicinity of the fruit trees. N. theisi preyed predominantly on pests of paddy (Nephotettix nigropictus, Oxya nitidula), wheat (Rhopalosiphum padi), citrus (Papilio demoleus) and guava (Bactrocera dorsalis) and to a lesser extent on damselflies, houseflies, and ants. C. citricola with smaller orb webs preyed upon N. nigropictus, R. padi, M. domestica, C. septempunctata, and C. compressus. Except the guava pest, B. dorsalis, the pests of paddy and wheat from the infested crops cultivated in the nearby ~ 500-m distant located farm were attracted by the streetlights and were preyed upon by the arboreal spiders. The results highlight the significant role of orb web spiders in the suppression of insect pests of crops and also provide direct evidence of the negative role of social spiders as predators of the Asian honeybee, A. cerana, and other beneficial insects.

Cotton (Gossypium hirsutum L.) has nectar containing modified stomates called nectaries that can be located on leaves, bracts or calyces. The nectar attracts some beneficial insects such as bees, but also predatory damaging insects such as heliothines and Lygus species. There is a naturally occurring mutation that eliminates the nectar containing nectaries and makes the cotton plants less attractive to insects. The nectariless (ne) trait is associated with a double recessive mutation of two genes (ne1 and ne2) on homeologous chromosomes 12 and 26. Expression of the trait can be variable and is also affected by environmental conditions. This makes accurately selecting for the trait based on phenotype difficult. This study identified SSR and SNP markers that can be used by breeders for marker assisted selection (MAS) of the nectariless trait. DNA markers associated with the genes conditioning the trait and used for MAS, will allow cotton cultivars to be easily developed that have decreased attractiveness to insects and reduce the need for insecticides, especially those harmful to beneficial insects such as honeybees.

Diversity of insect communities can be used as bioindicators for change in the environment especially in farms under different management systems. In line with that, we conducted a research on insect species associated with cocoa under organic and conventional management systems in the Eastern and Central regions of Ghana. Insect collection was done using Hand height visual count, Canopy, and “Knock down”, pitfall, coloured bowl and fruit-baited traps. A total of 13,742 individual insects belonging to 138 species from 63 families and 12 orders were recorded in the study. Insect abundance and diversity were generally higher in organic farms compared to conventional farms with Oecophylla longinoda as the most dominant species in both management systems and especially more dominant in organic cocoa farms. Our study revealed that most of the insect species recorded were known cocoa pests although there was high abundance of beneficial insects too. Some of the pest species were Planococoides njalensis, Salhbergella singularis, Helopeltis spp and Pseudococus spp, while some of the beneficial insects recorded were Pheidole spp, Tegenaria spp, Camponotus spp, Crematogaster spp. We can conclude that cocoa farms are potential habitats for insect biodiversity conservation. We recommend that management and/or agronomic practices used in cocoa farms should be geared towards protecting beneficial organisms for instance pollinators and natural enemies by effectively suppressing insect pest populations while enhancing good seed production.

Ladybeetles are known beneficial insects, with a long history in augmentative and classical biological control. The ladybeetle Oenopia conglobata (L.) is a natural enemy of many herbivores, particularly aphids. The temperature-dependent development of O. conglobata was studied at six constant temperatures (22.5, 25, 27.5, 30, 32.5 and 35 °C) to understand its development rate and environmental constraints better. Linear and nonlinear (Lactin) models were fitted to the data. In the thermal range from 22.5 to 32.5 °C, the rate of development increased for all stages; 35 °C was lethal for all stages and no eggs hatched. The Tb and K values for the biological cycle (egg–adult) were 8.84 °C and 263.15 DD, respectively. Depending on the model, tmin values for the total development time of the coccinellid ranged from 8.45 to 8.82 °C. The nonlinear model of Lactin estimated the optimum and upper temperature thresholds for the total development time of the ladybeetle to be 33.2 and 35.0 °C, respectively. High R2 values and low residual sum of squares values revealed a good fit to the experimental data for total development and different developmental stages of O. conglobata. The results may contribute to the improvement of practical methods for mass rearing of O. conglobata.

Mass rearing for commercial production of high quality beneficial insects is considered as an important tool for biological control programmes worldwide, especially those based on augmentative releases. Low temperature storage is a valuable method for increasing the shelf life of entomophagous insects. Insect predators and parasitoids are used extensively in biological control programmes and, because of this, studies on cold storage started over 90 years ago. The ability to store reared biocontrol agents at low temperatures for certain duration provides an opportunity to accumulate or stockpile sufficient number of entomophagous insects for field release at proper weather conditions and make them available during high demand periods to the concerned farmers. Cold stored natural enemies can be synchronously released in the fields during critical stages of pest outbreaks. Cold storage also helps to keep viable stock of natural enemies when not needed and to minimize laboratory operations by prolonging their survival and delaying eclosion. Cold storage tolerance is highly plastic trait influenced by a range of biotic and abiotic factors experienced before, during and after cold exposure. These factors ultimately affect the development, longevity, fecundity, parasitization, sex-ratio and other fitness parameters along with morphology, behaviour and physiology of entomophagous insects. For the successful implementation of a cold storage project, knowledge of these diverse factors that cause storage and post-storage effects is essential. The potential of cold storage protocols in improving mass rearing and commercial production of bioagents is thus reviewed to access the strategies, innovations, techniques, devices and wisdom involved in the process of cold storage of entomophagous insects worldwide.

Paved roadways, spanning 6.6 million kilometres across the continental United States, are often bordered by natural or restored habitats and could provide opportunities for pollinator conservation. Because insects are frequently killed by auto traffic, roadside habitats may be ecological traps that kill more pollinators than they produce. Here we compare insect traffic mortality when roadsides are bordered by woodlots, meadows, or lawns. We also compare study sites with and without restored medians to examine the impact of creating habitat that can only be accessed by crossing traffic. We confined our study to high speed roads (70–90 km h−1) with heavy traffic volume. Both habitat type and the presence of a vegetated median affect vehicle strikes fatal to insects. Insect mortality in general, and its effect on bees and butterflies in particular, was consistently lower when roads were bordered by woodlots than when they were bordered by lawn or meadows. Which roadside habitats were associated with the highest insect mortality depended on the taxon in question and the presence or absence of a vegetated median. Butterfly and dragonfly mortality was highest on roads with meadow medians, while bee mortality was highest on roadsides with lawn medians. Across most site comparisons, vegetated medians significantly elevated fatal insect-vehicle strikes. Regardless of the habitat bordering roadsides, insect mortality was unacceptably high for areas being considered for conservation. We suggest four research directions that may lead to reduced insect mortality in roadside habitats.

As cities expand, conservation of beneficial insects is essential to maintaining robust urban ecosystem services such as pollination. Urban warming alters insect physiology, fitness, and abundance, but the effect of urban warming on pollinator communities has not been investigated. We sampled bees at 18 sites encompassing an urban warming mosaic within Raleigh, NC, USA. We quantified habitat variables at all sites by measuring air temperature, percent impervious surface (on local and landscape scales), floral density, and floral diversity. We tested the hypothesis that urban bee community structure depends on temperature. We also conducted model selection to determine whether temperature was among the most important predictors of urban bee community structure. Finally, we asked whether bee responses to temperature or impervious surface depended on bee functional traits. Bee abundance declined by about 41% per °C urban warming, and temperature was among the best predictors of bee abundance and community composition. Local impervious surface and floral density were also important predictors of bee abundance, although only large bees appeared to benefit from high floral density. Bee species richness increased with floral density regardless of bee size, and bee responses to urban habitat variables were independent of other life-history traits. Although we document benefits of high floral density, simply adding flowers to otherwise hot, impervious sites is unlikely to restore the entire urban pollinator community since floral resources benefit large bees more than small bees.

Augmentation biological control has successfully replaced a lot of insecticide use in 'closed system' agriculture (e.g., greenhouses). The profitable commercialization of biocontrol agents in greenhouses has created an incentive to expand markets for mass-reared beneficial insects into open agricultural systems, often without sufficient scientific justification. However, the semi-contained nature of greenhouse culture is often critical to the success of augmentation and can serve to mask potential pitfalls and intrinsic limitations of this approach in open systems. Factors contributing to greenhouse successes include the reduced biological diversity of contained agroecosystems, the prevention of agent dispersal, the ability to maintain environmental conditions within a range favorable for the agent, the exclusion of competitors and natural enemies of the agent that might otherwise diminish its efficacy, and the absence of alternative prey/hosts that could divert predation/parasitism from the target pest. There are also problems arising from collection of source material from locally adapted populations, and the inadvertent imposition of artificial selection in the course of laboratory rearing. Besides highlighting these pitfalls, this paper aims to encourage more consideration of conservation approaches prior to investment in augmentation programs which entice farmers into perpetual cycles of 'rear and release.' I argue that although augmentation can benefit agriculture whenever it replaces pesticide applications, it does not constitute an ecologically sustainable solution because it requires continued inputs, and it can distract research attention away from more sustainable objectives. Sustainable biological control is best achieved through modifications to cultural practices that increasingly 'naturalize' agroecosystems, thus facilitating the natural recruitment and persistence of beneficial arthropod fauna, combined with habitat management geared to increasing overall plant and arthropod diversity in the agroecosystem.

Historic and current land-use changes have altered the landscape for grassland biota, with over 90% of grasslands and savannas converted to agriculture or some other use in north temperate regions. Reintegrating grasslands into agricultural landscapes can increase biodiversity while also providing valuable ecosystem services. In contrast to their well-known importance in tropical and subtropical ecosystems, the role of ants in temperate grasslands is often underappreciated. As consumers and ecosystem engineers, ants in temperate grasslands influence invertebrate, plant, and soil microbial diversity and potentially alter grassland productivity. As common and numerically dominant invertebrates in grasslands, ants can also serve as important indicator species to monitor conservation and management practices. Drawing on examples largely from mesic, north temperate studies, and from other temperate regions where necessary, we review the roles of ants as consumers and ecosystem engineers in grasslands. We also identify five avenues for future research to improve our understanding of the roles of ants in grasslands. This includes identifying how grassland fragmentation may influence ant community assembly, quantifying how ant communities impact ecosystem functions and soil processes, and understanding how ant communities and their associated interactions are impacted by climate change. In synthesizing the role of ants in temperate grasslands and identifying knowledge gaps, we hope this and future work will help inform how land managers maximize grassland conservation value while increasing multiple ecosystem services and minimizing disservices.

Barbarea vulgaris R. Br. and B. verna (Mill.) Asch (Brassicaceae) have been proposed as trap crops for the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae). In bloom, these plants could also be used to attract beneficial insects. In this study, we tested the attractiveness of flowering Barbarea to P. xylostella and to two of its parasitoids, Diadegma insulare Cresson (Hymenoptera: Ichneumonidae) and Diadromus collaris Gravenhorst (Hymenoptera: Ichneumonidae). We also tested whether the presence of flowering Barbarea planted in the field border could affect densities of 10 insect pests and two beneficial coccinellids in adjacent cauliflower plants. Flowering Barbarea did not change the densities of insects found in adjacent cauliflower, except for Eurydema ornata L. (Hemiptera: Pentatomidae), which densities on cauliflower were reduced by flowering B. vulgaris. Coccinellids were more abundant on flowering Barbarea than on cauliflower plants. Chrysomelids were also more abundant on flowering Barbarea than on cauliflower plants, while hemipteran and lepidopteran pests were often more abundant on cauliflower than on Barbarea plants. In plots with flowering B. vulgaris, P. xylostella pupae suffered 1.7 and 4.0 times more parasitism by D. insulare and D. collaris, respectively, than in plots without flowering B. vulgaris. Flowering reduced the attractiveness of Barbarea to P. xylostella, making it lose its effectiveness as a trap crop. However, being biennial, Barbarea could be used as a trap crop for P. xylostella the first year, and to lower the populations of E. ornata and increase parasitism of P. xylostella when it flowers the second year.

Spotted (Diabrotica undecimpunctata howardi) and striped (Acalymma vittata) cucumber beetles are significant pests of cucurbits, and organic management options are limited. Beetle feeding results in aesthetic damage and reduction in marketable yields as well as transmission of bacterial wilt resulting in plant mortality. Biopesticides are formulated from naturally occurring organisms such as fungi and bacteria that are pathogenic or toxic to insect pests and may be used in organic production systems. These products are thought to have lower risk to non-target organisms including mammals and beneficial insects. This research examined the potential of novel microbial products and fungal organisms to reduce cucumber beetle damage on melons. Laboratory bioassays were performed to evaluate the efficacy of a bacterial extract of Chromobacterium subtsugae and two common strains of entomopathogenic fungi, Beauveria bassiana and Isaria fumosorosea, on cucumber beetles in a controlled environment. Trials were performed against adult beetles in organic field experiments on muskmelon (Cucumis melo L. cv. reticulatus Ser.). Prior to testing in the field, anti-feedant effects were observed when beetles were exposed to leaves with Chromobacterium subtsugae and Beauveria bassiana in the laboratory. However, in field applications, we did not observe a reduction in beetle populations below the economic threshold levels, and subsequently, there was no yield increase compared to the control. Additional research is needed to improve biopesticide efficacy through formulation and timing of delivery, determine efficacy on multiple life stages of the pest, and understand interactions of microbial biopesticides in the environment and potential for non-target impacts in organic systems.

Ant pollination is a debated topic that requires more attention in order to clarify the role of ants as potential pollinators. Although many authors consider ants as mere nectar robbers, there are studies proving that ants may act as pollinators and that some plants even have flower traits acting as ant attractors. In this study, we evaluated the role of the ants in pollination of Blutaparon portulacoides inflorescences. This plant species has most of the traits favorable for ant pollination, such as short and aggregated inflorescences, and synchronized blooming as well as growing in an environment where ant pollination is likely to occur. Our results show that ants are the most abundant visitors throughout the day and that there is no effect of ant integument on pollen germination. Furthermore, the flower visitor exclusion experiment showed that ants have a role in the pollination of B. portulacoides by promoting seed formation. Ants can have an important part in the pollination of B. portulacoides in a scenario where winged insects are absent or scarce.

The European corn borer, Ostrinia nubilalis, is the most important pest insect of corn (Zea maize) in Germany, other European countries and historically in North America. However, in Europe only a few reports on naturally occurring biotic mortality factors are available. In the present review, an overview on pathogens including nematodes attacking O. nubilalis is compiled. The primary data were originally derived from long-term diagnostic studies on pathogens of arthropods carried out by the Institute for Biological Control, Darmstadt, Germany. These are updated with findings from the literature and supplemented with data from other pest insects of the same lepidopterous Crambidae family. The most important and most frequently found pathogens are the microsporidium Nosema pyrausta, the fungi Beauveria bassiana and to some extent also Fusarium spp., and the bacteria Bacillus thuringiensis and Serratia marcescens. Thus far, viruses have not been detected. Data on practical use of B. thuringiensis, B. bassiana and other fungi, N. pyrausta, and some nematodes for biological control of O. nubilalis are presented. Because of the importance of N. pyrausta as a population regulator of O. nubilalis, causing a chronic disease in larvae and adults, the current knowledge on the occurrence, biology, transmission, effects on the host insect, interactions with beneficial insects and field experiments is presented. These data are complemented with former, unpublished studies on the occurrence and incidence of N. pyrausta in some German and French O. nubilalis populations (Hessen, Baden-Wurttemberg, Alsace). The review clearly indicates that pathogens may play an important role as naturally occurring mortality factors of O. nubilalis which may also be used as biocontrol agents or within conservation biological control strategies.

Flubendiamide is widely used in agricultural fields to exterminate a broad spectrum of pests (lepidopteran insects) by disrupting their muscle function. The main objective of this study was to find the effects of flubendiamide on a non-target organism, Drosophila melanogaster (dipteran insect). In the present study, different sub-lethal concentrations of Flubendiamide caused a significant (P

Novel phenoxy derivative Juvenile Hormone Analogs (JHAs) – pyriproxyfen and diofenolan were used to evaluate their efficacy against last instar larvae of polyphagous pest Spodoptera litura. Sixth instar day 1-3 old larvae were treated with different doses of pyriproxyfen and diofenolan. The JHAs disrupted the growth, development, molting and metamorphosis in S. litura treated larvae. Both the JHAs-pyriproxyfen and diofenolan were found to be equally potent in their effects. The larval duration was prolonged apart from inducing several malformations. They effectively controlled the polyphagous pest S. litura by inducing mortality, ecdysial failure, production of larval – pupal mosaics, reduced pupation, production of abnormal pupae, complete suppression of normal adult emergence and production of deformed non-viable adultoids. Being stable, posing minimal threat to non-target organisms including fish and birds, beneficial insects and safe to environment and humans, both these JHAs can be judicially incorporated into IPM programs along with other bio-rational methods for the successful control of polyphagous pest S. litura.

Double-stranded RNA (dsRNA) designed to target pest genes emerges as a promising strategy for improving pest control. Therefore, it is necessary to assess the effects of dsRNA on non-target insects, such as native enemies and beneficial insects, to determine the environmental safety of such treatments. In this paper, we investigated the effects of dsRNA targeting rpl19 from Bactrocera dorsalis on non-target insects in citrus ecological systems by feeding the dsRNA to Bactrocera minax, Apis mellifera and Diachasmimorpha longicaudata. The results showed that when B. dorsalis were fed rpl19 CDS dsRNA or 3'UTR dsRNA, the expression of rpl19 was dramatically decreased. Feeding the Bdrpl19 CDS dsRNA to adult B. minax and D. longicaudata caused their respective rpl19 genes to be knocked down over 50-70 and 40%, respectively, but it had no effect on the expression of the rpl19 gene in A. mellifera. The Bdrpl19 3'UTR dsRNA did not have any silencing effects on the expression levels of rpl19 in non-target insects. This study provides evidence that dsRNA can impact non-target organisms, but the 3'UTR dsRNA may not have effects in non-target organisms.

Azadirachtin is a biorational insecticide commonly reported as selective to a range of beneficial insects. Nonetheless, only few studies have been carried out with pollinators, usually emphasizing the honeybee Apis mellifera and neglecting other important pollinator species such as the bumblebee Bombus terrestris. Here, lethal and sublethal effects of azadirachtin were studied on B. terrestris via oral exposure in the laboratory to bring out the potential risks of the compound to this important pollinator. The compound was tested at different concentrations above and below the maximum concentration that is used in the field (32 mg L(-1)). As most important results, azadirachtin repelled bumblebee workers in a concentration-dependent manner. The median repellence concentration (RC50) was estimated as 504 mg L(-1). Microcolonies chronically exposed to azadirachtin via treated sugar water during 11 weeks in the laboratory exhibited a high mortality ranging from 32 to 100 % with a range of concentrations between 3.2 and 320 mg L(-1). Moreover, no reproduction was scored when concentrations were higher than 3.2 mg L(-1). At 3.2 mg L(-1), azadirachtin significantly inhibited the egg-laying and, consequently, the production of drones during 6 weeks. Ovarian length decreased with the increase of the azadirachtin concentration. When azadirachtin was tested under an experimental setup in the laboratory where bumblebees need to forage for food, the sublethal effects were stronger as the numbers of drones were reduced already with a concentration of 0.64 mg L(-1). Besides, a negative correlation was found between the body mass of male offspring and azadirachtin concentration. In conclusion, our results as performed in the laboratory demonstrated that azadirachtin can affect B. terrestris with a range of sublethal effects. Taking into account that sublethal effects are as important as lethal effects for the development and survival of the colonies of B. terrestris, this study confirms the need to test compounds on their safety, especially when they have to perform complex tasks such as foraging. The latter agrees with the recent European Food Safety Authority guidelines to assess 'potentially deleterious' compounds for sublethal effects on behavior.

Oil seed rape (Brassica napus L.) is one of the most commonly grown crops in Central Europe, and the brassica pod midge (Dasineura brassicae Winn.) is one of the most important pests there. Insecticides against this pest applied during flowering may harm bees and other beneficial insects. The use of biostimulants such as nitrophenolates, which are not harmful to beneficial insects, can be an environmentally friendly way to control this pest. Nitrophenolates activate lignin synthesis in rape pods so the brassica pod midge is not able to penetrate pods. Nitrophenolates also regulate the efficiency of the photosynthetic apparatus, thus increasing yield. For these reasons nitrophenolates were tested in field conditions in Central Europe in 2005, 2007 and 2008. Nitrophenolates were applied on 10-m2 plots, and their effect was compared to that of conventional insecticides. The number of damaged pods and yield parameters were assessed; the lignin content as well as photosynthetic rate was measured. Expression of genes related to lignin biosynthesis was examined in Arabidopsis thaliana L. The application of nitrophenolates decreased pod damage caused by the brassica pod midge. Expression levels of four genes related to lignin biosynthesis were increased after the application of nitrophenolates. The yield was higher in nitrophenolate-treated plots, which was attributed to an increase in the intensity of photosynthesis, higher chlorophyll content and improved chlorophyll a fluorescence parameters. The results showed that nitrophenolates have potential as a protective agent, but a further study is required. The application of nitrophenolates holds promise for reducing chemical input into the environment.

Nectar guides can enhance pollinator efficiency and plant fitness by allowing pollinators to more rapidly find and remember the location of floral nectar. We tested if a radiating nectar guide around a nectary would enhance the ability of naïve bumble bee foragers to find nectar. Most experiments that test nectar guide efficacy, specifically radiating linear guides, have used guides positioned around the center of a radially symmetric flower, where nectaries are often found. However, the flower center may be intrinsically attractive. We therefore used an off-center guide and nectary and compared "conjunct" feeders with a nectar guide surrounding the nectary to "disjunct" feeders with a nectar guide separated from the nectary. We focused on the innate response of novice bee foragers that had never previously visited such feeders. We hypothesized that a disjunct nectar guide would conflict with the visual information provided by the nectary and negatively affect foraging. Approximately, equal numbers of bumble bees (Bombus impatiens) found nectar on both feeder types. On disjunct feeders, however, unsuccessful foragers spent significantly more time (on average 1.6-fold longer) searching for nectar than any other forager group. Successful foragers on disjunct feeders approached these feeders from random directions unlike successful foragers on conjunct feeders, which preferentially approached the combined nectary and nectar guide. Thus, the nectary and a surrounding nectar guide can be considered a combination of two signals that attract naïve foragers even when not in the floral center. © 2014 Springer-Verlag Berlin Heidelberg.

Many turf managers prefer to control foliage- and root-feeding pests with the same application, so-called multiple-targeting, using a single broad-spectrum insecticide or a premix product containing two or more active ingredients. We compared the impact of a neonicotinoid (clothianidin), a premix (clothianidin + bifenthrin), and an anthranilic diamide (chlorantraniliprole), the main insecticide classes used for multiple targeting, on four species of beneficial insects: Harpalus pennsylvanicus, an omnivorous ground beetle, Tiphia vernalis, an ectoparasitoid of scarab grubs, Copidosoma bakeri, a polyembryonic endoparasitoid of black cutworms, and Bombus impatiens, a native bumble bee. Ground beetles that ingested food treated with clothianidin or the premix suffered high mortality, as did C. bakeri wasps exposed to dry residues of those insecticides. Exposure to those insecticides on potted turf cores reduced parasitism by T. vernalis. Bumble bee colonies confined to forage on white clover (Trifolium repens L.) in weedy turf that had been treated with clothianidin or the premix had reduced numbers of workers, honey pots, and immature bees. Premix residues incapacitated H. pennsylvanicus and C. bakeri slightly faster than clothianidin alone, but otherwise we detected no synergistic or additive effects. Chlorantraniliprole had no apparent adverse effects on any of the beneficial species. Implications for controlling turf pests with least disruption of non-target invertebrates are discussed.

Tropical trees can provide various ecological services to adjacent agricultural environments, including maintaining and amplifying the numbers of beneficial insects. In Mexico, certain tree species harbor a diverse guild of hymenopteran parasitoids that attack pest fruit flies (Diptera: Tephritidae) and are at the same time sources of valuable hardwood timber. Indigenous trees and their associated fauna are slowly disappearing due to forest clearance and the expansion of crop monocultures. Here we explore the relationship among pest and non-pest fruit flies, their fruit-hosts and parasitoids in the context of mango orchards and surrounding patches of uncultivated vegetation and propose a novel mechanism to use these associations in favor of conservation purposes and pest management. Trees of conservation biological control interest are classified as: (1) parasitoid multiplier plants, species that serve as alternate hosts for key fruit fly pests when their commercial hosts are not available, but in which they are unusually vulnerable to parasitism; (2) parasitoid reservoir plants, native or introduced trees in whose fruits non-pest fruit flies serve as hosts to generalist parasitoids that are able to attack pest tephritids in other species of commercially grown fruit; and (3) pest-based parasitoid reservoir plants, native or introduced species that are not economically important locally, but which harbor fruit flies that would be pests in other circumstances and that serve as hosts for parasitoids of the important pests in the vicinity. Protection, multiplication and dissemination of such tree species has the potential to increase the number of naturally produced fruit fly parasitoids and could assist in the management of tephritid pests in areas where destruction of forests has impoverished the historical sources of fruit fly natural enemies. Tropical forest conservation may help resource-poor farmers reduce crop losses, increase biodiversity within fruit-growing regions and conserve native forests for both conservation purposes and commercial use of native hardwoods.

The integration of agroforestry plots with ephemeral crops such as vegetables on the farm scale can probably serve as a refuge and source of beneficial insects. Therefore, agroforestry systems possibly represent an alternative that favors ecosystem services and help growers in the transition process from conventional to agro-ecological agriculture. This study aimed to understand the role of introducing agroforestry systems in structuring insect communities, with consequences for the abundance of herbivore and natural enemies, contributing to farm management and favoring biological control as an ecosystem service. Field surveys showed that agroforestry systems can harbor more species than horticultural crops, independent of the functional group. They also contain a greater diversity of herbivores and an even greater diversity profile of natural enemy communities. Agroforestry systems served as a source of natural enemies that can colonize horticultural crops when herbivores are present. As a consequence, natural enemies can establish a numerical response to herbivore abundance, but their communities are also affected by stochastic factors related to climatic conditions. Thus, agroforestry systems and agro-ecological practices might favor an agriculture based on the maintenance and conservation of ecosystem services.

Non-crop vegetation in agricultural landscapes can provide a means of conserving insects in farmed landscapes and optimising on-farm ecosystem services as a result. Inclusion of floral resources may be particularly useful in conserving many beneficial insects, where groups including pollinators and pest natural enemies often rely on nectar and pollen during (at least part of) their life-cycle. As not all flowers are equally suited to all beneficial insects, selection of appropriate flowering plants is key to ensuring that conservation targets are met and benefits to ecosystems services realised as a result. This short paper describes an experiment conducted to assess the ‘total temporal attractiveness’ of a range of British wildflowers to selected functional insect groups. The results obtained demonstrate that flowering period alone is a poor indicator of plant suitability to insects, where no relationship existed between this and attraction to insects overall. Data also suggest that, based on attraction over a season, certain flowering plants are more likely to be of general insect conservation value and/or benefit to functional insect groups than others. Attraction to pest insects was also considered, with relatively high catches of thrips and pollen beetles observed in flowering stands of some plants.

Greenhouses in Turkey under integrated pest management can be colonized by a high number predatory flies of the species Coenosia attenuata Stein, 1903 (Muscidae: Coenosia Meigen, 1826). Studies have shown that Coenosia predators do not simply colonize greenhouses from the outside for short periods but instead they are able to complete their developmental cycle in the greenhouse soil and can become established there for a long period of time. C. attenuata is indigenous to the Palaeotropical region. Its prey spectrum includes whiteflies, black fungus gnats and leaf-mining flies. Studies of the natural occurrence of these predaceous flies in greenhouses led to a recognition of the significance of this complex of beneficials for the control of important greenhouse pests. They can build up effective populations under greenhouse conditions, and as non-specific predators can feed on a variety of pest groups and on innocuous species.

Fruit flies are pests of great economic importance due to their quarantine pest status and losses recorded in West Africa. An inventory of parasitoids associated with fruit flies in mangoes, guavas, cashew, pepper and major wild fruit crops was carried out in northern-central Benin in 2005, 2006, and 2008. Tephritid parasitoids reared from fieldcollected fruits belonged to three families: Braconidae (97.2%), Eulophidae (1.6%) and Pteromalidae (1.2%). Fopius caudatus (Sze´pligeti) accounted for 73.8% of all the parasitoids and therefore was the most abundant and widely distributed parasitoid. The parasitism rate was 7.7%, with the highest recorded in wild fruit crop habitat. Ceratitis cosyra (Walker) (77%) was the fly host most commonly reared from fruits that produced F. caudatus. The recently introduced pest Bactrocera invadens Drew Tsuruta and White was rarely parasitized and only by Pachycrepoideus vindemmiae (Rondani) (Hymenoptera: Pteromalidae) at this time. This is the first report of the inventory of one native parasitoid species from B. invadens in Africa, especially in West Africa.

Integrated pest management programs are very important in the control of invertebrate pests within apple orchards. Many current integrated pest management strategies concentrate on specialist predatory species. However, generalist beneficial insects, such as several mite species, must also be fully researched for their potential in controlling pests. Previous research has shown that the generalist predatory mite Anystis baccarum (Linnaeus) can offer much potential in controlling invertebrate pests within Northern Irish apple orchards. However, apple growers have been mis-identifying this beneficial species as the economic pest European fruit tree red spider mite, Panonychus ulmi (Koch). As a result, unnecessary pesticide applications have been applied against what has now been confirmed as a beneficial species. To aid apple growers in the identification of A. baccarum, identification cards were produced. Positive uptake of the cards by many apple growers has resulted in correct identification of A. baccarum from P. ulmi, and therefore, a reduction in chemical pesticide applications. The benefits of A. baccarum within orchard ecosystems is discussed.

With the widespread distribution of transgenic cotton plants, concerns over their potential effects on beneficial insects and other non-target pests have been raised. In the present study, the field and laboratory effects of Cry1Ac/CpTI transgenic cotton pollen on the pollinating beetle Haptoncus luteolus were investigated. Abundance of adult beetles was studied in cotton plots at two sites in Wuhan in 2009, and the average number of adults per flower was recorded. Life-history parameters including developmental duration, hatch rate, pupation rate, emergence rate and egg number per female, as well as the survivorship curves of H. luteolus were studied in laboratory experiments. The results showed that the adult abundance in the field did not differ significantly between non-transgenic and transgenic cotton, the exposure to Cry1Ac/CpTI pollen in laboratory had no effect on the developmental time, hatching rate, pupation rates and emergence rates of H. luteolus, no significant differences were found in the mating rates and the fecundity between treatments, and the survival curves of both treatments also resulted in no significant differences. It indicated there were no significant direct adverse effects of transgenic cotton pollen on H. luteolus both in the field and in the laboratory. Our study bridged the gap of environmental risk assessment of transgenic cotton for pollinators other than pollinating bees.

The green–blue network of semi-natural non-crop landscape elements in agricultural landscapes has the potential to enhance natural pest control by providing various resources for the survival of beneficial insects that suppress crop pests. A study was done in the Hoeksche Waard to explore how generic scientific knowledge about the relationship between the spatial structure of the green–blue network and enhancement of natural pest control can be applied by stakeholders. The Hoeksche Waard is an agricultural area in the Netherlands, characterized by arable fields and an extensive network of dikes, creeks, ditches and field margins. Together with stakeholders from the area the research team developed spatial norms and design rules for the design of a green–blue network that supports natural pest control. The stakeholders represented different interests in the area: farmers, nature and landscape conservationists, water managers, and local and regional politicians. Knowledge about the spatial relationship among beneficial insects, pests and landscape structure is incomplete. We conclude that to apply scientific knowledge about natural pest control and the role of green–blue networks to stakeholders so that they can apply it in landscape change, knowledge transfer has to be transparent, area specific, understandable, practical and incorporate local knowledge.

International audience; The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is the most important pest of cultivated Brassica worldwide, including those grown in greenhouses like cauliflower. In this article, we evaluate the potential of various species (and various strains of some species) of Trichogrammatidae (Hymenoptera: Chalcidoidea) to control this pest on cauliflower in greenhouse in France. We assessed the parasitism levels on P. xylostella of 17 Trichogrammatidae strains, belonging to 12 different species (2 indigenous strains from France), under greenhouse conditions. Parasitism levels for each of the Trichogrammatidae species and strains were determined on cauliflower leaves (Brassica oleracea botrytis L., Brassicaceae) infested with P. xylostella eggs. Nine strains parasitized 60% (or more) of the P. xylostella eggs. Compared to previous results in laboratory conditions, climatic conditions of the greenhouse did not influence parasitism levels. The presence of the cauliflower plants may have a positive effect on eight strains, a negative effect on four strains and no effect on five strains. Our study points out the importance of including the host plant of P. xylostella when conducting studies aiming to select the most efficient parasitoid against this pest.

Production of biofuel feedstocks in agricultural landscapes will result in land use changes that may have major implications for arthropod-mediated ecosystem services such as pollination and pest suppression. By comparing the abundance and diversity of insect pollinators and generalist natural enemies in three model biofuel crops: corn, switchgrass, and mixed prairie, we tested the hypothesis that biofuel crops comprised of more diverse plant communities would support increased levels of beneficial insects. These three biofuel crops contained a diverse bee community comprised of 75 species. Overall, bees were three to four times more abundant in switchgrass and prairie than in corn, with members of the sweat bee (Halictidae) and small carpenter bee (Ceratina spp.) groups the most abundant. Switchgrass and prairie had significantly greater bee species richness than corn during the July sampling period. The natural enemy community at these sites was dominated by lady beetles (Coccinellidae), long-legged flies (Dolichopodidae), and hover flies (Syrphidae) which varied in their response to crop type. Coccinellids were generally most abundant in prairie and switchgrass, with the exception of the pollen feeding Coleomegilla maculata that was most abundant in corn. Several rare or declining coccinellid species were detected in prairie and switchgrass sites. Dolichopodidae were more abundant in prairie and switchgrass while Syrphidae showed no significant response to crop type. Our results indicate that beneficial insects generally responded positively to the increased vegetational diversity of prairie and switchgrass sites; however, when managed as a dedicated biofuel crop, plant and arthropod diversity in switchgrass may decrease. Our findings support the hypothesis that vegetationally diverse biofuel crops support higher abundance and diversity of beneficial insects. Future policy regarding the production of biofuel feedstocks should consider the ecosystem services that different biofuel crops may support in agricultural landscapes.

Bracomorpha ninghais sp. n. (Hymenoptera: Braconidae) is described and illustrated based on individuals reared from the immature stages of the pine sawyer Monochamus alternatus (Coleoptera: Cerambycidae) in Zhejiang of China, which is considered a notorious forest pest associated with the main vector of the pine wood nematode Bursaphelenchus xylophilus (Nematoda: Aphelenchoididae) in China.

Laboratory studies were conducted to determine the effects of Trioxys angelicae Haliday (Hym.: Braconidae) age and host density (Aphis fabae Scopoli) (Hem.: Aphididae) on selected attributes of parasitoid reproductive biology. The number of hosts parasitized per day was used as an estimate of wasp fecundity. Parasitoid longevity was not affected by host density and at host densities of 2, 4, 6, 8, 10, 15, 20, 30, 40 or 60 aphids per day; the parasitoids lived an average of 8.96 ± 0.82 days at 21°C. At host densities of ≤20 aphids per day, lifetime fecundity of a single Trioxys angelicae female was limited by the number of hosts available. Lifetime fecundity was highest with an average of 158.14 ± 20.33 at a density of 30 aphids per day; the maximum number of aphids parasitized by any female was 235. Daily fecundity and sex ratio were affected by parasitoid age and host density. Age-specific fecundity at different host densities fitted well to a nonlinear model. In conclusion, the fecundity and female progeny production of Trioxys angelicae as an important biological control agent of A. fabae is influenced by host availability.

Laboratory trials were conducted to test the side-effects of the insecticides chlorpyrifos-methyl, buprofezin, pyriproxifen, spinosad and a narrow range mineral oil on Aphytis melinus DeBach, Coccophagus lycimnia Walker (Hymenoptera: Aphelinidae) and Leptomastix dactylopii Howard (Hymenoptera: Encyrtidae). The effects of chlorpyrifos-methyl, spinosad and pyriproxifen were also investigated in semi-field conditions on L. dactylopii. Contact toxicity on adult female parasitoids after 24, 48 and 72 h, the effects on their fertility as well as the sex ratio of the progeny were measured. In the laboratory trials chlorpyrifos-methyl and spinosad caused 100% mortality on all tested parasitoids just 24 h after the treatment. According to the IOBC classification, the mineral oil was slightly harmful on L. dactylopii; buprofezin was harmful on C. lycimnia, and slightly harmful on L. dactylopii and A. melinus; pyriproxifen resulted moderately harmful on C. lycimnia and slightly harmful on L. dactylopii and A. melinus. The progeny production of each L. dactylopii surviving female treated with buprofezin was not affected by the treatment while in the case of A. melinus it was significantly reduced. C. lycimnia females treated with pyriproxifen did not produce any progeny. In semi-field conditions the tested insecticides were less harmful to L. dactylopii adults but, although none of them influenced the progeny production of the survived females, the longevity was negatively affected.

Insects provide essential ecological services in both the natural environment and in human-dominated habitats. Because pollinator declines associated with land use change have been reported across the globe, there is great concern that pollinators and the ecosystem services they provide will be negatively affected. This study examines the diversity and abundance of bee pollinators in grasslands in Boulder County, Colorado, USA. Over five years, 5,200 bees were collected in grassland plots with different levels of urbanization. Most of the difference in species composition among three levels of urbanization was due to rare species that may not have been discovered in all plots. Neither the number of species nor their abundance differed significantly among the plot types, although the trend indicated increasing diversity with increasing distance from urbanization. Most notably, measures of urbanization, such as the amount of pavement and development, were not correlated with diversity. The most important factor affecting bee abundance, particularly for ground-nesting bees, was grazing regime. Bee abundance also was positively related to the number of flowering plant species. Other studies of different insects (grasshoppers and butterflies) in these plots showed results similar to ours. In contrast, previous studies on song-birds, raptors, and rodents showed significant differences between urban edge and remote plots in terms of organism abundance and diversity. Together, these results suggest that factors other than the degree of urbanization are important in determining insect abundance and diversity.

Historic species lists for a region can be of great interest to biologists surveying modern faunas. In 2001, we initiated a 5-year field study to examine the status of insect pollinators in Boulder County grasslands, Boulder, Colorado. Century-old records of the bee fauna were available from bee specialist Cockerell’s publication (University of Colorado Studies, Boulder, 1907) The Bees of Boulder County. We predicted that 116 species originally found by Cockerell would occur in grassland habitats. We recorded 110 species, including several species not present in the 1907 collection. We conclude that the bees of the grasslands of Boulder County have been largely conserved, and we hypothesize that the large amount of preserved habitat in the county has contributed to maintaining the insects.

In olive orchards, which are very common in the Mediterranean region, cover crops are becoming increasingly used to counter problems of erosion. Although such plant covers can provide food and shelter for beneficial insects, mites, and spiders, they may also attract pests. In order to determine their relationships with the main pests in olive orchards, an analysis was made of adult population levels and damage caused in five olive-cultivation zones, in olive orchards with cereal-crop covers and in olive orchards with conventional tillage. The effects of the cereal cover crops on insect pest populations were different and in some cases in opposite direction. Thus cereal cover crops had no impact on the different studied pests, including all those that spend part of their development cycle in the soil, such as Bactrocera oleae, Prays oleae, or Otiorrhynchus cribicollis. However, under certain conditions some pests did show an increase in abundance. Diverse trophic relationships should be investigated in this agroecosystem in future studies in order to develop appropriate crop-management policies.

Invasive species are generally detected in new ecosystems long after their first arrival, making it difficult to elucidate pathways leading to successful invasion. In this study, the dispersal of a classical biological control agent, the mymarid egg parasitoid Gonatocerus ashmeadi, was monitored across ten islands in three major island groups in French Polynesia from the exact moment of its introduction into Tahiti to combat the invasive pest Homalodiscavitripennis. Within 10 months, the parasitoid spread quickly from Tahiti to widely separated islands (up to 1,400 km from Tahiti); presumably through the transportation of plant material containing parasitized H. vitripennis eggs. Gonatocerus ashmeadi thus functioned as a “biomarker”, providing an informal audit of the effectiveness of inter-island quarantine measures designed to curb the accidental spread of noxious organisms. Survey results suggest that invasive organisms, like deliberately released biological control agents, can be unintentionally and rapidly transmitted across vast distances by humans. Furthermore, even remote islands appear to experience relentless pressure from invasive propagules associated with human travel. Implications of survey work documenting the spread and impact of G. ashmeadi are discussed within the context of biological control programs, non-target impacts, and biosecurity initiatives.

The parasitoid wasp Pnigalio agraules (Wlk.) is a key natural enemy of the horsechestnut leafminer Cameraria ohridella Deschka and Dimic (Lepidoptera: Gracillariidae). As a basis for mark-release-recapture studies, aimed at investigating the dispersal of this parasitoid in the field, adults of P. agraules were marked using a vertebrate-specific immunoglobulin (IgG). The marker was later detected by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). The IgG was either applied externally by spraying or internally by feeding an IgG-enriched diet. Different concentrations of the marker were used and the influence of abiotic (climatic conditions, time elapsed between marking and marker examination) and biotic factors (sex and age of the parasitoids) on the detection of the immunomarker was tested. External marking by spraying led to more homogeneous labelling than feeding the marker. Parasitoids labelled with 0.25 mg rabbit IgG per ten individuals contained enough immunomarker to be easily distinguished from unmarked ones. Neither the climatic conditions nor the sex or age of the insects had an influence on the detection of the marker. The IgG remained well detectable during the entire lifespan of the parasitoids, which was not negatively affected by the marking procedure. Serological marking can be used to investigate the dispersal behaviour of beneficial insects within mark-release-recapture studies.

Damages caused by the larvae of Byturus tomentosus (Coleoptera: Byturidae) are a big problem of European raspberry production. Under integrated pest management conditions in Switzerland, B. tomentosus is controlled by chemical-synthetic insecticides. In organic production, no corresponding insecticides are permitted. White sticky traps (type Rebell® bianco) are used for monitoring purposes. Can glue-traps also be used for mass-trapping and damage control? In this study, the attractiveness for adult B. tomentosus of one yellow and several white glue-traps was compared by counting the trapped individuals. Trapped beneficial insects like honey bees, Coccinellidae, Syrphidae and Chrysopidae were also counted. The contamination of the traps caused by other non-target arthropods was measured by a computer-assisted method. The white sticky trap type Rebell bianco was the most attractive for B. tomentosus. The attractiveness for the beneficials was relatively low, except when too much glue was applied on the traps, then the attractiveness for honey bees increased significantly. In this study, traps, which were placed in high densities (17 traps per 100 m2), significantly decreased the damages caused by larvae by around 40%. The trapping method does not cause any residuals of pesticides on the fruits or soil. Therefore, the trapping method could be an alternative to control B. tomentosus, especially in organic production.

Fifteen synthetic herbivore-induced plant volatiles (HIPVs) were field-tested for attractivity to beneficial insects in two experiments conducted in an open field and a hop yard in Washington State. Eleven insect species or families showed significant attraction to 13 HIPVs. The ladybeetle, Stethorus punctum picipes, was attracted to sticky traps baited with methyl salicylate (MeSA), cis-3-hexen-1-ol (He), and benzaldehyde (Be). The minute pirate bug, Orius tristicolor, was attracted to traps baited with MeSA, He, Be, and octyl aldehyde (Oa), and the bigeyed bug, Geocoris pallens, responded to MeSA, indole, and trans-2-hexen-1-al. The mymarid wasp, Anagrus daanei, was attracted to He, Oa, and farnesene. The chloropid fly, Thaumatomyia glabra, was highly attracted to methyl anthranilate. Insect families responding to HIPVs included Syrphidae (MeSA, He), Braconidae ((Z)-3-hexenyl acetate, He, cis-jasmone (J), methyl jasmonate (MeJA), methyl anthranilate (MeA)), Empididae (MeSA), Sarcophagidae (MeSA, Be, J, nonanal and geraniol), Tachinidae (Be), and Agromyzidae (MeSA). Micro-Hymenoptera (primarily parasitic wasp families) were attracted to MeSA, He, and indole. These results are discussed with respect to known properties and bioactivity of the tested HIPVs and to their potential as tools for recruiting natural enemies into agroecosystems.