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Background: Although the pupal parasitoid Trichopria drosophilae is used in conservative and augmentative biocontrol of Drosophila suzukii infestations, current pest management strategies mostly rely on multiple insecticide applications. In this context, the aim of the study was to investigate the baseline toxicity of nine insecticides on D. suzukii larvae and their multiple sublethal effects (LC10) on immature stages of the pest feeding on contaminated diet and T. drosophilae developing within the intoxicated host. Results: Chlorpyriphos and azadirachtin showed the lowest and the highest LC10, the values of which were 9.78 × 1013 and 1.46 × 103 times lower than their recommended label field rate, respectively. Among tested insecticides, imidacloprid, malathion and dimethoate were the only treatments that did not affect the juvenile development time of D. suzukii, while spinosad and the organophosphates chlorpyriphos and dimethoate did not influence fly pupal size. No sublethal effects were recorded on T. drosophilae degree of infestation (DI) and juvenile development time. On the contrary, cyazypyr and dimethoate negatively affected the success of parasitism (SP) and the number of progeny of the pupal parasitoid, in association with malathion for the first parameter and spinosad for the fertility. Compared to the untreated control, more female progeny emerged following azadirachtin exposure, while dimethoate caused the opposite effect. Imidacloprid, lambda‐cyhalothrin and spinetoram decreased hind tibia length of emerged parasitoids. Conclusion: This study provides new insights on the (eco)toxicological profile of nine insecticides and new information needed to support the deployment of T. drosophilae in the field within the sustainable management techniques against D. suzukii. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Exploiting plant defense mechanisms is a promising tool for pest management in modern agriculture. Plant Essential Oils (EOs) are used for the sustainable control of agricultural pests; however, their impact on plant defense has been scarcely investigated. In this work, we study for the first time whether the spraying of EOs can activate plant defense mechanisms in sweet pepper. The olfactory capacity of Encarsia formosa (Hymenoptera: Aphelinidae) to respond to defenseactivated plants was used to select garlic and peppermint EOs among nine EOs sprayed on sweet peppers. The expression level of defense-related genes in plant tissues and the phytotoxicity were measured in response to EO foliar applications. Moreover, the olfactory responses of the herbivores, Bemisia tabaci (Hemiptera: Aleyrodidae) and Frankliniella occidentalis (Thysanoptera: Thripidae), and their natural enemies, Orius laevigatus (Hemiptera: Anthocoridae) and Nesidiocoris tenuis (Hemiptera: Miridae), to EO induced plant volatiles were also investigated. The gene expression analysis revealed activated jasmonic and salicylic acid defense signaling pathways in EO-sprayed sweet pepper plants and a negligible phytotoxic effect was recorded. Choice tests revealed varying behavioral responses in selected insect models when plants were treated with garlic and peppermint EOs in different concentrations. Our results suggest that garlic and peppermint EO spray applications can enhance the defense mechanisms of sweet peppers and have a cascading bottom-up effects on the associated food chain. These initial findings provide a foundation for the future development of Integrated Pest Management strategies to protect solanaceous crops. [ABSTRACT FROM AUTHOR]

Systemic insecticides are used to control agricultural pests globally and their non-target impact at non-lethal doses on beneficial arthropods has been recognized. We assessed the baseline toxicity of imidacloprid, thiamethoxam and sulfoxaflor-based insecticides on the polyphagous aphid pest, Aphis gossypii (Hemiptera: Aphididae), and their non-target effects on its main parasitoid, Aphidius colemani (Hymenoptera: Braconidae), evaluated by residual contact exposure to the median lethal (LC 50), the low lethal (LC 20) and the sublethal (LC 1) concentrations of the three tested insecticides, earlier estimated for the target pest. The results showed that the LC 50 s for the aphid were 6.4 × 10−3, 5 × 10−3, 2.9 × 10−2 times lower compared to the label concentrations of imidacloprid, thiamethoxam and sulfoxaflor, respectively. LC 50 of thiamethoxam caused the highest mortality rate on the parasitoid followed by sulfoxaflor, while imidacloprid had the lowest impact. No significant sublethal effects on reprodution were observed for A. colemani survived to the insecticide exposure. Our findings highlight the importance of case-specific evaluation to optimize pesticide applications in Integrated Pest Management packages taking into account the ecological services provided by biological control agents. • Systemic insecticides were toxic against the cotton aphid at lower concentrations compared to label indications. • Non-lethal pesticide concentrations estimated for the target pest affected differently the parasitoid survival. • Case-specific evaluations in insecticide risk-assessment are recommended even at very low doses. [ABSTRACT FROM AUTHOR]