This study investigated flight activity to develop forecasting methods for adult Eysarcoris aeneus（Scopoli）entry into rice fields. We examined the effects of temperature（30°C and 25°C）and food on flight muscle development and flight activity. Flight muscle weights were significantly higher at 25°C than at 30°C. At both temperatures, most males maintained their flight muscles as they aged. Female flight muscle weights decreased at both temperatures due to histolysis, with a more rapid reduction at 30°C than at 25°C in younger females. Oviposition rates showed no significant differences between the two temperatures. The rapid histolysis of female flight muscles at 30°C likely reflects higher maintenance costs at this temperature than at 25°C, thereby influencing the duration of female flight activity. Additionally, given the developmental transition of the flight muscles, flight activity may differ between male and female E. aeneus. Under feeding conditions, the number of flying individuals within 30 days after eclosion was higher at 30°C（16 individuals）than at 25°C（5 individuals）and higher in females（20 individuals）than in males（1 individual）. Females began flying an average of 5.7 days after eclosion at 30°C, compared with 11.8 days at 25°C. These findings demonstrate that temperature influences the number of flying individuals and the duration of flight activity in E. aeneus, especially in adult females. Food availability was essential for flight muscle development in adults after eclosion. Under 25°C conditions, removing food significantly increased the number of flying individuals compared with feeding conditions, with no significant differences observed between males and females. This indicates that unfavorable feeding conditions enhance E. aeneus activity. In conclusion, temperature and food interact to influence the flight activity of E. aeneus, affecting the timing and number of adults entering rice fields.
Mitsuyoshi Yao (2026) studied this question.