Threshold-dependent gene regulation and partial assortative mating determine wing dimorphism of an Insect

Wing dimorphism is a fantastic life-historical trait of insects which indicates the developmental trend of populations, going as migrants or staying as residents. The alternative wing morph enhances adaptability of insects to changing environments. However, the underlying mechanism for maintaining wing dimorphism remains vague. The brown planthoppers Nilaparvata lugens, a serious pest of rice, are either short-winged or long-winged. The shift between two wing morphs is determined by two insulin receptors. So, this pest is a better model organism to explore the mechanism of wing dimorphism. Here, the short- and long-winged strains of N. lugens were selected. Rates of a selected wing morph were linearly increased in populations, and the selection response of the short-winged morph was stronger than that of the long-winged. Selection enhanced the migratory or resident propensity. Directional selection for the long-winged morph resulted in longer and lighter forewings, while selection for t..., , ,