• body-color polymorphism;
  • field census;
  • rearing experiment


The effects of five environmental factors, background color, density, humidity, photoperiod and temperature, on the body color of a pyrgomorphid green/brown polymorphic grasshopper, Atractomorpha lata, were examined in rearing experiments, in which the differences in color morph frequencies between males and females were also examined. Field censuses were conducted to determine whether the sex difference in body-color polymorphism occurs under field conditions. Among the environmental factors examined, temperature was the only factor that significantly affected body color: the frequency of brown morphs tended to be higher at higher temperatures. The frequency of brown morphs in the female was higher than in the male, a consistent finding in both the rearing experiments and the field censuses. The threshold temperature at which body color changes may be lower in the female than in the male.