Tendency to mate with short-winged partner of the brown planthopper Nilaparvata lugens (Hemiptera: Delphacidae)

Abstract Wing dimorphism is a distinguishing characteristic of brown planthopper Nilaparvata lugens (Stål) populations, wherein adults exhibit 2 distinct morphs: long-winged and short-winged. The presence of long-winged individuals often heralds the onset of migration, while short-winged morphs signify high reproduction and can be associated with population outbreaks. This phenomenon underscores the adaptability of these insects in response to environmental cues and their impact on agricultural ecosystems. Wing morphs of N. lugens are controlled by genetical and environmental factors. Mate choice between long and short-winged adults affects wing morphs of offspring. In this study, we found that the wild population had no persistent preference for choosing long-winged or short-winged adults to mate. But in 2 multigenerational selected lineages for long and short-winged morphs, the short-winged males preferred to short-winged females to mate and the long-winged males had no preference. In the nearly pure-bred lineages of long-winged and short-winged morphs, both wing morphs of females preferred for short-winged males. Purification of wing morph lineages enhanced mating preference for short-winged partners. When the wing developmental gene InR1 or InR2 was interfered by RNAi, the pure-bred lineage of long-winged morph mainly produced short-winged adults and the short-winged morphs produced long-winged adults, and these adults exhibited preference to mate with short-winged partners. The tendency to mate with short-winged morphs leads to more short-winged offspring which easily causes the rapid growth of populations.