起始供食时间对稻水象甲冬后成虫繁殖、取食和存活的影响

Effects of Initial Time of Rice Plant Availability on Reproduction, Feeding and Survival of Overwintered Rice Water Weevil (Lissorhoptrus oryzophilus)

室内研究了稻水象甲冬后虫在春季获得寄主水稻前所经历的时间长短对其产卵、取食和存活的影响。供试虫 (4月下旬采集 )先用禾本科草坪草高羊茅饲养 0、1 0、2 0、30和 45 d(即供食水稻前时间 ) ,然后用 2 0～ 35 d龄的稻苗饲养 ,观察产卵等情况。结果表明 ,水稻供食前时间达到 1 0 d后即可致使冬后虫产卵历期明显缩短 ,卵量下降 ,取食斑的数量和长度减少。当水稻供食前时间延长至 2 0 d后 ,成虫在水稻上的存活历期开始明显下降。处理时间越长 ,对其后成虫在水稻上的生殖、取食和存活的影响越大。

Overwintered adults of rice water weevil (RWW), Lissorhoptrus oryzophilus, were reared previously with Festuca eluta Keng for 0, 10, 20, 30 and 45 days (periods before seedling availability) respectively, and then with rice seedlings till all adults died at 28±1℃ in the laboratory. Results showed that even a short period (10 days) before rice seedling availability could lead to a significant reduction in ovipositional periods, fecundity, feeding scar number and length on seedlings. The treatments ≥20 days resulted in significant declines in adult survival periods on rice seedlings. The longer periods the adults experienced before seedling availability, the more decrease occurred in their fecundity, feeding and survival. Relationships between periods before rice availability and occurrence of the first generation weevil in rice were discussed.