白蜡外齿茎蜂形态与生物学特性观察

Observation on morphological and biological characteristics of Stenocephus fraxini Wei

经采集、饲养和剖检观察,确认目前在北京、天津、河北、山东危害白蜡树Fraxinus spp.枝梢髓部的害虫是白蜡外齿茎蜂Stenocephus fraxini Wei,而非白蜡哈氏茎蜂Hartigia viatrix Smith。白蜡外齿茎蜂在山东商河1 a发生1代,以老熟幼虫在1 a生枝条内越夏,以预蛹越冬。成虫羽化高峰期在4月上旬或中旬,集中而短暂;雌雄性比平均为1.94∶1,孕卵量23(12~43)枚。明确了成虫产卵部位和卵的分布,产卵于1 a生枝梢茎部和复叶叶轴上;卵历期7~10 d,幼虫孵化至老熟历期50~70 d;老熟幼虫在1 a生枝条部位以基部最多,中部次之,端部最少。

After collection,breeding and necropsy observation,it was confirmed that the pest attacking the pinch of Fraxinus spp.shoots in Beijing,Tianjin,Hebei Province and Shandong Province was Stenocephus fraxini Wei,but not Hartigia viatrix Smith.S.fraxini Wei had one generation per year in Shanghe,Shandong Province,and old larvae were oversummered in one year growth branches and overwintered as prepupae.The peak period of adult emergence was in early or mid-April,which was concentrated and short.The ratio of male to female was 1.94:1,and the number of pregnant eggs was 23(12~43).The egg laying sites and distribution of eggs was determined,and the eggs were laid in stems of one year growth shoot and rachises of compound leaf.Egg duration was 7 to 10 days,and larvae took 50 to 70 days from hatching to maturity.The number of mature larvae was the most in the base of one year growth branch,the next was in the middle,the least was in the end of the branch.