小云斑鳃金龟生物学特性研究

Study on Biological Characteristics of Polyphylla gracicornis

小云斑鳃金龟在白龙江林区4年1代,以幼虫在土壤中越冬。越冬幼虫于每年4月上旬上升为害,至10月下旬下迁越冬,活动范围为10～25cm,越冬深度以40～70cm居多。成虫始发期为6月中旬,盛期为7月中、下旬;田间幼虫孵化盛期为8月上、中旬。各虫态的历期:蛹期29d,卵期26d,1龄幼虫340d,2龄幼虫365d,3龄幼虫700d,成虫16d。成虫雌雄性比1.2∶1,昼伏夜出,21:00～23:00为出土活动高峰,雄虫有极强的趋光性,雌虫的趋光性极弱。成虫不取食,雌虫产卵为单粒散产,产卵量平均为26粒,多产于15cm耕作层的卵室中。土层深厚、富含有机质及含水量适宜的地块虫害发生较重。

Polyphylla gracicornis generate 1 generation in 4 years and live through the winter by larva. The larva living through the winter start to damage the forest in early April every year and live through the winter in late October. Its activity range is 10～25 cm in soil and the soil depth in which it live through the winter is 40～70 cm. Its imago generate in middle June and dominant period is in middle and late July; the dominant hatching period of larva is in early and middle August. The duration of pupa is 29 days, ovum is 26 days, larva with 1 instar is 340 days, larva period with 2 instars is 365 days, larva period with 3 instars is 700 days and imago period is 16 days. The ratio of female and male imago is 1.2:1, and they are active in the day and keep quiet at night and the active peak time is 21:00～23:00. The imago is free from food. The female imago oviposit sporadically and they average amount of ovum are 26, mainly oviposit in the soil with depth of 15cm. The land with deep soil, appropriate water and rich nutrient is subject to damages of these insects.