Transcriptome analysis of neuropeptides in the beneficial insect lacewing ( Chrysoperla carnea ) identifies kinins as a selective pesticide target: a biostable kinin analogue with activity against the peach potato aphid Myzus persicae

The common green lacewing Chrysoperla carnea (Neuroptera), also called the aphid lion, is an important predator of pest species, especially aphids that cause serious damage in many crops in agriculture. Neuropeptides are involved in regulating various physiological processes in insects. However, there have not been many studies on the neuropeptides found in C. carnea . This study aimed to assemble and define a whole body- and head-specific transcriptome of C. carnea . Interestingly, we found 41 candidate neuropeptide genes to encode precursors, but 10 neuropeptide genes were not found, including kinin. Based on this original hypothesis that this important neuropeptide was lost during evolution in this important natural enemy, it will lose its effect when we expose C. carnea to kinin neuropeptide analogue. Therefore, we tested three kinin analogues 1728, 2460 and 2139, and assessed their effect on the survival of the important green-peach aphid ( Myzus persicae ) via topical application. We found that the 2460 analogue [HCA-R(Aib)WGa] effectively controlled aphids, leading to 46% mortality within 5 days post-exposure. In contrast, 2460 showed no significant lethal or sublethal effects on survival, food intake and weight increase, in the beneficial insect C. carnea . In conclusion, this work suggests that kinin analogues may offer biosafe insecticide compounds, and in turn promote the development of more biosafe and sustainable integrated pest management (IPM) pest control strategies that are based on the combination of peptide analogues and natural enemy insects.