Insecticidal efficacy and risk assessment of different neuropeptide analog combinations against the peach‐potato aphid following topical exposure

Abstract

Background: Insect neuropeptides control essential physiological metabolic activities. In our previous studies, Capability/ CAP2b (PK/CAPA) analog 1895 applied alone or as a combination of CAPA analogs (1895 + 2315) was reported to decrease aphid fitness. While this was obtained with the combination of two peptide analogs of the same neuropeptide class, the effect of combining peptide analogs of different neuropeptide classes has not been explored so far.Results: In this study, we assessed the effect of combinations of the PK/CAPA analog 1895 with neuropeptide analogs of four different classes [adipokinetic hormone (AKH) analog: 2271; myosuppressin analog: 2434; kinin analog: 2460; tachykininrelated peptide analog: 2463] on the fitness of aphids. We found that the combination of 1895 and AKH analog 2271 was the most effective one to control Myzus persicae. The triple combination 1895 + 2271 + 2315 provided a synergistic effect by further increasing aphid mortality and reducing reproduction relative to 1895 + 2315. Additionally, a biosafety assessment of the combination 1895 + 2271 + 2315 showed no significant lethal nor sub-lethal effects on survival rates and food intake for the pollinator (Bombus terrestris) and the two representative natural enemies (Harmonia axyridis and Nasonia vitripennis).Conclusion: These results could facilitate establishment of the triple combination 1895 + 2271 + 2315, and/or inclusion of second generation analogs, as alternatives to broad spectrum and less friendly insecticides.

Transcriptome of Excretory Organs Revealed Potential Targets for the Control of Nilaparvata lugens

“…Peptide analogs of diuretic or antidiuretic factors may be useful as pest control agents because severe ionic and osmotic homeostasis disruption may lead directly to insect mortality. Potent insecticidal effects of CAP2b analogs have been previously demonstrated. − For example, CAPA analogs 1895, 2315, and their combinations were reported to be effective in controlling aphids and have no adverse influences on beneficial insects. , Insecticidal activities by agonistic compounds are expected to differ greatly from the results of inhibitory activities by RNAi of the signaling component. Whether the neuropeptide signaling system in the excretory organs of BPH could be a potential pest control target must be further studied through more RNAi and peptidomimetics testing efforts.…”

“…48−50 For example, CAPA analogs 1895, 2315, and their combinations were reported to be effective in controlling aphids and have no adverse influences on beneficial insects. 49,50 Insecticidal activities by agonistic compounds are expected to differ greatly from the results of inhibitory activities by RNAi of the signaling component. Whether the neuropeptide signaling system in the excretory organs of BPH could be a potential pest control target must be further studied through more RNAi and peptidomimetics testing efforts.…”