Toxicity and Influence of Sublethal Exposure to Sulfoxaflor on the Aphidophagous Predator Hippodamia variegata (Coleoptera: Coccinellidae)

Abstract

Hippodamia variegata (Goeze), the variegated ladybug, is a predator of many insect pests, especially aphids. Sulfoxaflor is a chemical insecticide that can be used to control many sap-feeding insect pests, for instance, plant bugs and aphids, as an alternative to neonicotinoids in different crops. To improve the combination of the H. variegata and sulfoxaflor in an IPM (integrated pest management) program, we studied the ecological toxicity of the insecticide to the coccinellid predator at sublethal and lethal doses. We examined the influence of sulfoxaflor on larvae of H. variegata using exposure doses of 3, 6, 12, 24, 48 (maximum recommended field rate (MRFR)), and 96 ng a.i. per insect. In a 15-day toxicity test, we observed decreased adult emergence percentage and survival, as well as an increased hazard quotient. The LD50 (dose causing 50% mortality) of H. variegata due to sulfoxaflor decreased from 97.03 to 35.97 ng a.i. per insect. The total effect assessment indicated that sulfoxaflor could be grouped as slightly harmful for H. variegata. Additionally, most of the life table parameters were significantly decreased after exposure to sulfoxaflor. Overall, the results present a negative influence of sulfoxaflor on H. variegata when applied at the recommended field dose for controlling aphids in Greece, which demonstrates that this insecticide may only be employed with care when used in IPM programs.

Fitness effect and transcription profile reveal sublethal effect of nitenpyram on the predator Chrysopa pallens (Neuroptera: Chrysopidae)

“…septempunctata and Hippodamia variegate (Coleoptera: Coccinellidae) (Skouras et al, 2023a;Wang et al, 2023). This phenomenon was not observed in the present study, probably due to the different test methods.…”

“…Similarly, the sublethal dose of imidacloprid treatment had no adverse effect on preadult survival rate, GRR , r , R 0 , λ , and only prolonged T of C. pallens (Su et al, 2023). In addition, it was found that sublethal doses of sulfoxaflor significantly reduced the population parameters of C. septempunctata and Hippodamia variegate (Coleoptera: Coccinellidae) (Skouras et al, 2023a; Wang et al, 2023). This phenomenon was not observed in the present study, probably due to the different test methods.…”