A STUDY ON CHYLIZA BAMBUSAE

Chyliza bambusae Yang et Wang is a main pest damaging the roots of bamboo shoots. In Zhejiang province, most of them have one generation a year, but few of them per two years, and both overwintered in the pupal stage. Its eclosion starts in early March when the averaged day temperature is above 12℃,and ends in late April. Larvahs infestation period is from middle April to late May. The bamboo shoot roots growing in the middle or low slope and on the fertile soil will be damaged heavily. In the even year bamboo stand will be damaged more seriously than those in the on-year stand located far away from the off-year stand. After being endangered, the roots left will be around lOcm length with no absorbing and supporting function so that the death rate of bamboo shoots will increace, and although some of them can still grow,the new culms will have sharp shape and are easy to lodge.There are two species of natural enemies of its larvae from Braconidae and Diapriidae, which have parasitic percentage of 26.08%and 12.18%respectively.In its peak stage of eclosion, it is a useful method to eliminate its imagoes by spraying diluted solution of 80%DDVP 1:1000.