荔枝蒂蛀虫夜间生活习性观察

Observation on the Nocturnal Behaviors of Conopomorpha sinensis Bradley

荔枝蒂蛀虫是为害荔枝、龙眼的重要害虫,其以孵化后的幼虫蛀入果实为害,形成“虫粪果”,严重影响荔枝品质和产量。在荔枝品种混栽果园的自然条件下,在果实膨大期蒂蛀虫羽化高峰后每天20时至翌日5时30分用手机电筒和普通手持小电筒照射下观察树冠叶层间、叶面和果实,调查记录蒂蛀虫成虫在自然条件下夜晚活动行为习性。结果表明:蒂蛀虫从傍晚开始迁飞至树冠叶层间和叶面及果实上活动,至完全天黑时基本离开枝干,天空开始发出光亮时又返回枝干处;20时左右开始产卵,高峰时段为20时30分至22时30分,24时后基本停止产卵;产卵位置多集中在果肩和果蒂部位的龟裂片凹陷处,每雌每次在果肩部产卵2~3粒、在果实中部产卵1~2粒,呈散产状,且在果实上产卵时不受同类卵的影响;蒂蛀虫成虫交尾时间在1时至4时之间;正在产卵和交尾的成虫未表现出明显的畏光现象,但在产卵和交尾前明显迁至避光照环境。本研究为荔枝蒂蛀虫防治提供了一定的依据和参考。

The Conopomorpha sinensis Bradley is a type of injurious insect that damages litchi and longan.It lays eggs on the litchi fruit,and its larvae live inside and damage the fruit by discharging excrement,which severely affects the quality and yield of litchi.Under the natural conditions of a mixed planting litchi orchard,the nocturnal behaviors of the imagos of C.sinensis in the fruiting stage after the insect’s eclosion was observed.The observation was conducted from 20:00 P.M.to 5:30 A.M.the next day,and C.sinensis’behavioral patterns were observed and recorded by close examination on treetops,leaves and fruits with the help of torchlight and cell phone flashlight.The result showed that after the eclosion,the adult insects flew to the leaf layer and fruits in the canopy at nightfall.When the sky turned completely dark,they almost all left the tree trunk,and then returned to the branches again at dawn.The spawning started at around 20:00 P.M.,and the peak period was from 20:00 P.M.to 22:30 P.M..The spawning stopped at around 24:00 P.M.,with most of the eggs being laid on the skin segments of the shoulder and the stem of litchi fruit.Each female insect layed 2-3 eggs at the shoulder of the fruit at a time,and 1-2 eggs in the middle of the fruit.The eggs were scattered,and the female’s spawning behavior was not affected by pre-existing eggs laid on the fruit by another female.The mating period of the adult insects was between 1:00 a.m.and 4:00 a.m.During mating and spawning,the adult insects did not show obvious photophobia.However,before mating and spawning,the C.sinensis moved noticeably to a dark environment.This study provided a basis and reference for the prevention and control of C.sinensis.