粟穗螟发生为害与寄主种类及其生育期的关系

STUDIES ON THE ERLATIONS BETWEEN THE OCCURENCE OF THE FOXTAIL MILLET WEBWORM (Mampava bipunctella Rogonot) AND THE GROWTH PERIOD OF HOST VARIETIES

四川粟穗螟的寄主植物有高粱、玉米和小米。寄主最适合成虫产卵的生育期是高粱、小米杨花期,玉米抽雄散粉期。幼虫历期、存活率、滞育率、一生为害粒数、雌蛹重量因寄主及生育阶段不同而异。田间粟穗螟幼虫密度主要由寄主适宜成虫产卵生育期相遇时间的长短所决定。

The host plants of Foxtial Millet Webworm Nampava bipunctella Rogonot in Sichuan province are sorghum, corn and millet. The optium growth period for adult insects to deposit the eggs are at the flowering stages of sorghum and millet and the staminate pollen spreading stage of corn. It is distinctly different in larva period, survival rate, stagnant growth rate, injured grain number in larval stage and weight of female chrysalis of the webworm according to different hosts and different growth stages of various crops. The larval density in the fields is mainly dete- rmined by the length of coincident period of the occurence of the adutl insects and the suitable period for oviposition in the growth periods of the hosts.