Effect of food stress on flight muscle and reproduction development in a wing dimorphic cricket, Velarifictorus ornatus Factors of influencing the development of wing dimorphism in the rice white-backed planthopper, Sogatella furcifera Horvth Effects of genetic and environmental factors on wing dimorphism in a subtropical population of Modicogryllus confirmatus Walker Effects of environmental factors on wing differentiation in Velarifictorus aspersus Walker