THE OOGENESIS FLIGHT SYNDROME OF RICE WATER WEEVIL, Lissorhoptrus oryzophilus Kuschel
稻水象甲(Lissorhoptrus oryzophilus Kuschel)的卵子发生-飞行共轭

The seasonal migration and oogenesis flight syndrome of the rice water weevil(RWW), Lissorhoptrus oryzophilus Kuschel,in the double rice cropping area of Zhejiang Province was studied from 1994 to 1996.The flight muscles of RWW undergo cyclic degeneration and regeneration with the seasonal migration to and from aestivo hibernation sites and show an obvious oogenesis flight syndrome.The over wintered adults migrate to the early rice fields in spring to produce a damaging generation.All of the newly emerged adults are in a state of reproductive diapause and possess well developed flight muscles and hypertrophic fat bodies.Most of them fly to dormancy sites with aestival autumn hibernal diapause,only a few individuals,that land to rice seedling fields or still stay in the paddy fields when the late rice transplanting strats,will develop to next generation.The adults emerge in the autumn migrate to hibernation sites.but the weevils emerged since the second half of October will not develop their flight muscles and will stay at the fields or ridges for hibernation.If high quality foods are provided,regeneration of the flight muscles of the aestival weevils will occur,and the newly emerged adults will first develop their flight muscles and then break down their reproductive diapause.