Lethal and sublethal effects of seven insecticides on three beneficial insects in laboratory assays and field trials

Abstract

Lethal and sublethal effects of insecticides on target and non-target arthropods are a concern of pest management programs. Cycloneda sanguinea, Orius insidiosus and Chauliognathus flavipes are important biological control agents for aphids, whitefly, lepidopterus eggs, thrips and mites. All three test species were subjected to a toxicity study using the insecticides acephate, bifenthrin, chlorantraniliprole, chlorpyrifos, deltamethrin, imidacloprid, and thiamethoxam. Experiments were done in the lab and field. In the laboratory we evaluated the mortality and sublethal effects of the concentration that killed 20% of the population (LC20) on feeding, repellence and reproduction of the species tested. The lethal effects of these insecticides at the recommended doses was evaluated in the field. Concentration-response bioassays indicated chlorantraniliprole had the lowest toxicity, while chlorpyrifos and acephate were the most toxic. Test species exposed to filter paper surfaces treated with pyrethroids, neonicotinoids and organophosphates were repelled. On the other hand, test species were not repelled from surfaces treated with chlorantraniliprole. Chlorantraniliprole therefore seemed to be the least dangerous insecticide for these three beneficial arthropod test species.

Variation in susceptibility and selection for resistance to imidacloprid and thiamethoxam in Mediterranean populations of Orius laevigatus

“…Systemic applications of imidacloprid and thiamethoxam had direct toxicity for Orius insidiosus (Say) (Phrabaker et al, 2011). Using filter paper residual tests it was found that imidacloprid was more toxic for O. insidiosus than thiamethoxam (LC 50 = 0.08 vs. 0.38 mg cm À2 ) (Fernandes et al, 2016). These results are similar to those obtained in other recent assays (Phrabaker et al, 2017).…”

Lethal and sublethal effects of chlorantraniliprole on Spodoptera cosmioides (Lepidoptera: Noctuidae)

“…In the present research, although the differences were not significant between treatments, we also found that the number of emerged adult insects decreased in the second generation, when the insecticide was applied, with negative consequences for population dynamics. With these somewhat conflicting results in mind, it is worth noting that chlorantraniliprole is still the most effective compound for use against defoliating caterpillars, while having low lethal and sublethal effects on beneficial arthropods …”

Neonicotinoid insecticides negatively affect performance measures of non‐target terrestrial arthropods: a meta‐analysis

“…, Fernandes et al. ). However, organismal response to neonicotinoids is influenced by sensitivity to active ingredients and exposure concentrations (Whitehorn et al.…”

“…, Scholer and Krischik , Fernandes et al. ). In our analysis, active ingredient explained <10% of total heterogeneity between studies, and although significant, there were no differences between effects of active ingredients.…”

“…, Fernandes et al. ). Similar discrepancies exist for other species including honeybees, native bees, butterflies, and earthworms (Blacquiere et al.…”