格木人工林内荔枝异形小卷蛾的生活史及其防治

Life History of Cryptophlebia ombrodelta(Lepidoptera:Tortricidae) and Comprehensive Control in Erythrophleum fordii Plantation

格木(Erythrophleum fordii)是我国热带南亚热带地区一个珍贵用材树种,受荔枝异形小卷蛾(Cryptophlebia ombrodelta)蛀梢危害严重。采用野外调查和室内饲养相结合的方法,研究其生活史及各发育阶段特征,分析其各幼虫龄期特征及其在格木嫩梢的为害习性。实验室条件下,荔枝异形小卷蛾卵的发育历期平均为3.72d,其孵化可全天发生;幼虫平均为20.43d,可划分为5个龄期,各龄期头壳宽度和发育时间均随龄期上升呈指数增加;预蛹平均为3.28d,蛹历期平均为8.67d,14:00-16:00为蛹羽化高峰期;成虫寿命平均为9.38d,雌虫寿命大于雄虫;一个世代约45.48d。在广东省中部格木人工林内1a可发生5代,第1代幼虫在3月中旬开始出现,4月中旬化蛹,4月下旬见成虫;第2～4代幼虫分别出现的时间为5月中旬、7月上旬和8月中旬,第5代从9月下旬持续至翌年3月,在格木人工林其通常以幼虫在其枝梢内越冬,有世代重叠现象。该虫在格木人工林内可大面积持续发生,同时为害多个嫩梢,幼虫钻蛀孔道长度平均为67.22mm,为害高峰期为6-7月,即第2、3代为害最严重。基于荔枝异形小卷蛾生活史和格木生物学特性,探讨其防控方法及可行性,为开展格木人工林蛀梢害虫科学防控提供技术支撑。

Erythrophleum fordii （Caesalpiniaceae） is a valuable timber species in tropical and subtropical area in South China,and its plantations were damaged by Cryptophlebia ombrodelta （Lepidoptera：Tortricidae） severely.The life history and characteristics of each stage of C.ombrodelta were investigated through field survey in plantations of E.fordii combined with artificial feeding.The characteristics of larval instars and its damage on E.fordii were analyzed so as to provide scientific evidences for its control.The duration of C.ombrodelta eggs was 3.72 days,and their hatching occurred all day under laboratory condition.The duration of larvae averaged 20.43 days and could be divided into five instars,insect head carapace widths and duration of each instars increased exponentially with larva development.The durations of prepupae and pupae averaged 3.28 and 8.67 days,respectively,and the peak of pupae eclosion were at 14：00-16：00.The mean adult longevity was 9.38 days,and the longevity of female was longer than that of male,each generation averaged about 45.48 days. C.ombrodelta occurred 5 generations in E.fordii plantation in the middle region of Guangdong Province.The larvae of the first generation initiated in mid-March with pupae in mid-April and adult in late April,the second to fourth generation larvae appeared in mid-May,early July and mid-August,respectively,the fifth generation lasted from late September to the next year March,and larvae usually was overwintering in E.fordii shoots,the overlapping generations was common.It could occurred continuously in large scale in E.fordii plantations,and infected young shoots massively at the same time,shoot length of boring averaged 67.22 mm.Pest occurrence peak continued from June to July,the damages of the second and third generations were more serious.The prevention and control method and feasibility of C.ombrodelta were discussed based on its life history and E.fordii biological characteristics,which would provide technical supports for scientific prevention and control about this shoot borer in E.fordii plantations.