短室缘茧蜂生物学特性

Biology of Perilitus xynus Chen et van Achterberg(Hymenoptera: Braconidae: Euphorinae)

短室缘茧蜂(Perilitus xynus Chen et van Achterberg)内寄生于林业害虫榆紫叶甲(Ambrostoma quadriimpressum)成虫,通过野外调查和室内观察,对其生物学特性进行了研究。结果表明:该茧蜂在哈尔滨1年发生2代,在寄主体内以初孵幼虫越冬;幼虫共3龄,幼虫在寄主体内发育期消化道的废物不排出体外;老熟幼虫离开寄主后在浅土层内结茧化蛹,在室内温度为(25.0±0.5)℃、相对湿度(65±5)%、光暗周期比16∶8情况下,蛹期为16.6 d;成虫在不交配并取食10%蜂蜜水补充营养的情况下,平均寿命为5.0d,饲养条件为(23±1)℃、相对湿度(45±5)%、光暗周期比16∶8;雌蜂将产卵器扎入寄主头胸间的颈膜,把卵产在寄主血淋巴中;雌雄成虫性比接近1。2017年,野外短室缘茧蜂的寄生率为38.8%,单个寄主平均寄生22.3头,寄主雌雄两性的被寄生率和单头寄主的寄生蜂数量无差异。

Perilitus xynus is a natural enemy of adult Ambrostoma quadriimpressum . The biology of P. xynus was studied in both fields and laboratories. The braconid completes two generations one year in Harbin and overwinters as 1 st instar larva in the host. The larva has three instars and does not excrete from the anal during development within the beetle. Mature larvae exits out and pupates with a cocoon in topsoil. The pupa development time is 16.6 d （25 ℃±0.5 ℃, 65%±5% RH, 16L∶8D）. The life span of unmated adults, feeding on 10% honey, is 5.0 d （23 ℃±1 ℃, 45%±5% RH, 16L∶8D）. Female lays eggs into host’s hemolymph by pushing the ovipositor through membranous cervicum between head and thorax. The sex ratio is about 1. In 2017, the natural rate of parasitism was 38.8%, and a single beetle can host a mean of 22.3 wasps, which are not significantly different between sexes.