Analysis of lethality of cypermethrin, imidacloprid and chlorantraniliprole on Chrysoperla nipponensis (Neuroptera: Chrysopidae)

The conservation of natural enemies can help in the effort to improve biological control. Selection of the appropriate insecticide is necessary in controlling pest populations to ensure the least side effects on non-target insects. In this study, the insecticide efficacy (Et), initial versus final efficacy (E0 vs. E5), insecticide efficacy change over time and lethality index of cypermethrin, imidacloprid and chlorantraniliprole were evaluated against the larvae of green lacewings, Chrysoperla nipponensis (Neuroptera: Chrysopidae), a general predator of insect pests. The third instar larvae were exposed to dry residue at the label recommended field rate for 2 hours. The immediate impact of insecticides and the recovery and mortality rates of individual larvae over a 5 days period were observed. Among three insecticide, cypermethrin showed a moderate initial efficacy where 10% < E0 < 90%, while imidacloprid and chlorantraniliprole were low in initial efficacy (E0 ≤ 10%). All evaluated insecticides showed increasing efficacy where the percentage of moribund and dead larvae increased by > 10% after 5 days. The lethality index for cypermethrin was 72.7% and followed by imidacloprid, 32.5%, and chlorantraniliprole, 11.2%. Consequently, cypermethrin showed the highest toxicity on larvae of C. nipponensis compared with other insecticides.

Text FP 2016 45 - IR.pdf Download (1MB)

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