草地螟成虫活动与幼虫发育的观察

草地螟地面种群一般在夜间活动。成虫以21:00时至午夜在蜜源植物丰富的植被环境内活动最为频繁,在多种杂草和作物上产卵,卵多产在幼虫寄主植株的中、下部。幼虫3龄前多在卵寄主植物上栖息取食。测定了20℃和30℃恒温条件下饲育的幼虫头部、胸部宽度和身体长度。提出鉴别草地螟幼虫龄期时应按幼虫的头宽再辅以体长或胸宽,田间幼虫发生调查应侧重成虫活动频繁、幼虫喜食植物较多的植被环境。

The Observation of Adult Activity and Larva Development of Meadow Moth( Loxostege sticticalis L.)

The field population activity of meadow moth,(Loxostege sticticalis L., generally occurred on night time. The most frequent activity of adults occurred in the vegetation with abundant forage plants from 21 o'clock to midnight. Adults laid eggs on a lot of weeds and crops, and most eggs were laid on the middle or lower part of plants. Most of the larvae inhabited or fed on the egg host plants before they were the third instar. The width of cephalosome and baenosome and the length of cirpus of the larvae in every instar were determined. These larvae were separately fed under the condition of constant temperature of 20℃ and30℃. The distinguish methods of different larvae stage were put forward, i.e. which was on the basis of the cephalosome width with the cirpus length or baenosome width. It was suggested that the field survey of larvae occurrence should lay particular emphasis on the vegetation of frequent occurrence of adults or abundant host plants of larvae.