Sensitive Period Of Wing-morph Determination In The Brown Planthopper

The brown planthopper (Nilaparvata lugens) is an important pest of rice in china and many Asian countries. The adult BPH (brown planthoppers) have two wing forms, which is a special biological phenomenon that the nymphal brown planthoppers can selectively develop into macropterous or brachypterous adults. Brachypterous adults can not fly but can produce eggs in great volume, macropterous adults can migrate when the environmental conditions get worse. Hence, researches about the plasticity of wing development in BPH have great significance to the insect evolutionary developmental biology. So far, the sensitive period of wing-morh determination in BPH is still not clear, It is reported that the insulin signaling pathway can regulate wing dimorphismin brown planthopper. Based on the regulation of insulin receptors (NlnR1 and NlnR2) to wing dimorphism, we carried out a study about sensitive period for wing dimorphism in fifth stadium nymphs. Here are the main results:(1) the sensitive period for wing dimorphism lasts to the early-fifth stadium (24h after molting) in females; (2) the sensitive period for wing dimorphism lasts to the mid-fifth stadium (42h after molting) in males; (3) the transcription factor foxo mediates the wing dimorphism; (4) cell proliferation in the wingbud is the primary cause for long-wing formation, (5) preliminary obtained the gene expression profiles data during the sensitive period of wing dimorphism. Our findings about the sensitive period are of great significance for understanding the wing-morph plasticity mechanism.In addition, these findings have an important practical value in predicting and forecasting BPH occurrence.