通过室内饲养与野外观察榆木蠹蛾Holcocerus vicarius(Walker)成虫的羽化、交尾、产卵行为,触角电位反应测定处女雌蛾性信息素产生与释放节律,旨在为榆木蠹蛾性信息素的鉴定和合成奠定基础。结果表明:榆木蠹蛾羽化行为全天可见,主要集中在15:00-19:00。成虫羽化当日即可交尾,21:30-0:30进行婚飞和交尾,交尾高峰出现在晚23:00左右,光期未见交尾。随着日龄的增加,召唤时间前移并且延长,2~3日龄处女雌蛾召唤时间早于1日龄雌蛾,交尾时间较短;雌蛾在羽化1d后达到性成熟,2日龄雌蛾交尾百分率最高,达41.8%。雌蛾将产卵器伸出寻找缝隙处产卵,分多处产卵,雌虫最高产卵量达720粒,最低产卵量为105粒,卵期为12~22d不等,孵化率为72%~88%。羽化当晚的雌蛾体内性信息素含量较低,第2天最高,以后逐日下降;2日龄榆木蠹蛾处女雌蛾性信息素的产生量从晚17:00起逐渐增加,21:30-22:00时最高,22:00后逐渐减小。雄蛾触角电位反应在22:30最强。21:30-23:00是雌蛾产生和释放性信息素的高峰期。榆木蠹蛾的羽化、交尾存在一定的时辰节律,通过处女雌蛾的野外诱集试验证实了性信息素释放与交配行为在时辰节律上的一致性。
To establish the basis for identifying and synthesizing the sex pheromone of Holcocerus vicarius(Walker),the eclosion,mating and oviposition of H.vicarius adults were studied by means of observations and experiments both in the fields and laboratory.The circadian rhythm of sex pheromone production and release of H.vicarius was studied by means of electroantennogram(EAG) response.The results showed that the eclosion of H.vicarius happened throughout the day,especially from 15:00 to 19:00.Mating behavior started on the 1st night after the eclosion and the nuptial flight and mating took place from 21:30 to 0:30.The peak of mating occurred at 23:00 or so.The mating behavior was not observed during the photophase.Calling varied with the age of female,with older(2 to 3-day-old) virgin females calling earlier and for longer duration than younger(1-day-old) females.They had shorter time of mating when they were young.Females became sex mature one day later.The percentage of mating of 2-day-old was the highest(41.8%).The females searched the gap with ovipositor,and then began to oviposit.They oviposited at various places.The maximum of oviposition was up to 720 eggs,and the minimum was 105 eggs.The egg stage lasted 12-22 d.The hatch rate was from 72% to 88%.The amount of pheromone in the gland was relatively low on the first night after the eclosion,with a peak during the second night,and then decreased gradually when they aged.The amount of pheromone of 2-day-old virgin females began to increase gradually post 17:00,with the peak between 21:30 and 22:00,and then decreased gradually post 22:00.EAG response was the greatest at 22:30.The peak of sex pheromone production and release of H.vicarius occurred between 21:30 and 23:00.There was a circadian rhythm in the eclosion and mating of adults.The sex pheromone release and mating behavior of H.vicarius were synchronized,which was confirmed by tests of using virgin females to trap males in the fields.