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Building on an exercise that identified potential harms from simulated investigational releases of a population suppression gene drive for malaria vector control, a series of online workshops identified nine recommendations to advance future environmental risk assessment of gene drive applications.

Genetically engineered gene drives (geGD) are potentially powerful tools for suppressing or even eradicating populations of pest insects. Before living geGD insects can be released into the environment, they must pass an environmental risk assessment to ensure that their release will not cause unacceptable harm to non‐targeted entities of the environment. A key research question concerns the likelihood that nontarget species will acquire the functional GD elements; such acquisition could lead to reduced abundance or loss of those species and to a disruption of the ecosystem services they provide. The main route for gene flow is through hybridization between the geGD insect strain and closely related species that co‐occur in the area of release and its expected dispersal. Using the invasive spotted‐wing drosophila, Drosophila suzukii, as a case study, we provide a generally applicable strategy on how a combination of interspecific hybridization experiments, behavioral observations, and molecular genetic analyses can be used to assess the potential for hybridization. [ABSTRACT FROM AUTHOR]

Genetically engineered (GE) cotton, MON 88702, is protected against certain sucking pests, such as plant bugs and thrips, by producing mCry51Aa2, a modified protein from Bacillus thuringiensis (Bt). Predatory pirate bugs (Orius spp.), natural enemies contributing to biological pest control, are also sensitive to the insecticidal protein when exposed continuously to high concentrations. We evaluated effects of MON 88702 on Orius majusculus when fed prey types with different mCry51Aa2 concentrations. When neonates were provided exclusively Tetranychus urticae spider mites reared on MON 88702 (high mCry51Aa2 content), adverse effects on predator survival and development were confirmed, compared with specimens fed prey from near‐isogenic non‐Bt cotton. When fed a mixture of T. urticae and Ephestia kuehniella eggs (mCry51Aa2‐free), predator life table parameters were similar to the treatment where eggs were fed exclusively. When mCry51Aa2‐containing spider mites were provided for a limited time at the beginning or the end of juvenile development, effects were less pronounced. While pirate bug nymphs showed similar consumption rates for prey from Bt and non‐Bt cotton, choice experiments revealed a preference for E. kuehniella eggs over spider mites. Lepidopteran larvae (Spodoptera littoralis, high mCry51Aa2 content) or cotton aphids (Aphis gossypii, mCry51Aa2‐free) reared on MON 88702 as alternative prey did not result in adverse effects on O. majusculus. Our study suggests limited risk of mCry51Aa2‐producing cotton for O. majusculus, because its sensitivity for the Bt protein is relatively low and its natural food consists of diverse prey species with varying concentrations of Bt protein. [ABSTRACT FROM AUTHOR]

Extreme climatic events, including heat waves with high‐temperature peaks during the day, are expected to occur more often in many parts of the world due to climate change and may exert negative effects on existing biological control strategies. To assess the effects of high‐temperature peaks on two commonly used, and naturally co‐occurring mirid predators, adults and nymphs of Nesidiocoris tenuis and Macrolophus pygmaeus were exposed either to constant 25°C or daily mean temperatures of 25°C with cycles rising up to 30 or 40°C. Preferred location of the two mirid species on different strata of tomato plants was investigated when they were exposed to the different temperature regimens alone or combined. Activity of mirids under the different temperature regimens was continuously monitored for 48 h using a Drosophila Activity Monitor system. Finally, the efficacy of the mirids preying on Tuta absoluta eggs was measured at the different temperature regimens in a Petri dish assay. Heat waves reaching 30 and 40°C in some instances affected the location of the mirids either when they were on the plant alone or under competition conditions. Locomotory activity of M. pygmaeus in the 40°C treatment was strongly reduced, whereas it remained high in N. tenuis. Effects of temperature peaks on prey consumption were visible in M. pygmaeus nymphs, N. tenuis females and males of both species. We suggest that the different responses of the two species to high‐temperature peaks may reduce their competition and support sustained control when both species are present simultaneously. Moreover, both species were found to be less susceptible to heat peaks when compared to previously reported results for their prey T. absoluta. [ABSTRACT FROM AUTHOR]

BACKGROUND: Combining different biocontrol agents, particularly micro‐ and macroorganisms, can contribute to new and sustainable pest control approaches. Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most destructive pests of solanaceous crops. An emerging management strategy consists of biological control using microbial insecticides such as baculoviruses, but with limited efficacy. Thanks to their high target specificity, baculoviruses can be used simultaneously with natural enemies such as parasitoids for improved control of T. absoluta. However, potential indirect nontarget effects of baculoviruses on parasitoids can result from overlapping resource requirements. We assessed whether ovipositing parasitoid females discriminated against virus‐treated hosts and examined the outcome of within‐host competition between the hymenopteran parasitoids Necremnus tutae (Reuter) (Eulophidae) and Dolichogenidea gelechiidivoris Marsch (Braconidae), and the Phthorimaea operculella granulovirus (PhopGV, Baculoviridae) that infects T. absoluta larvae. RESULTS: Female D. gelechiidivoris discriminated against virus‐treated hosts, whereas N. tutae did not. We found few indirect virus‐related effects depending on the species, the sex, and the time of virus treatment. Effects were ambivalent for D. gelechiidivoris offspring and ranged from increased male longevity when infection occurred before parasitization to reduced emergence and male longevity when infection occurred after parasitization. N. tutae offspring showed a longer development time and shorter male longevity when they developed in virus‐treated hosts. CONCLUSION: The virus had a low impact on parasitoid offspring. In rare cases, adverse effects were detected; however, the low magnitude of these effects is unlikely to reduce the fitness of parasitoid offspring, therefore both parasitoids seem compatible with the baculovirus for control of T. absoluta. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]