刀角瓢虫的生物学特性及其与小黑瓢虫形态特征的比较

刀角瓢虫与小黑瓢虫是烟粉虱的2种重要捕食性天敌,对烟粉虱的危害具有很好的控制作用.本文对刀角瓢虫的生物学特性,包括生活史、取食习性、化蛹习性、羽化与交配习性、产卵习性、成虫寿命与耐饥力,以及2种瓢虫的形态特征进行研究.结果表明:刀角瓢虫在福州1a发生6-7代,以成虫越冬;在实验室条件下,卵期、1龄、2龄、3龄、4龄、预蛹及蛹的历期分别为5.23、2.4、1.98、1.90、1.75、2.96、5.18d,完成1个世代约需19.5-24.5d,平均历期21.5d;世代存活率0.68;雌成虫寿命(63.6±21.0)d(n=10),雄成虫寿命(51.6±11.7)d(n=10),故雌成虫寿命比雄成虫长;单雌产卵总量75-257粒,平均(136.8±57.8)粒(n=10);雄成虫的耐饥力较雌成虫大,但二者最长的耐饥时间均不超过108h.

Biological characteristics of Serangium japonicum and its morphology in comparion with Delphastus catalinae

 Serangium japonicum Chapin and Delphastus catalinae Horn are important natural enemies of Bemisia tabaci . The biological characteristics of S. japonicum including life history, feeding behaviour, pupation, mating, oviposition, longevity of adults and the comparative morphology of the two kinds of coccinellids were studied. The results were as follows: S. japonicum developed 6-7 generations a year in Fujian Province and it overwintered in the form of adult; developmental times for eggs, 1st, 2nd, 3rd, 4th instars, pre pupae and pupae were 5.23, 2.40, 1.98, 1.90, 1.75, 2.96, 5.18 days respectively, with an average of 21.5 d from oviposition to adult emergence for a generation, ranging from 19.5 to 24.5 d; survival rate of a generation was 68%; longevity of adults of S. japonicum was (63.6±21.0) d (n=10) for females and (51.6±11.7) d (n=10) for males; a female laid 75-257 eggs, averaging (136.8±57.8) eggs (n=10); male adults could tolerate starving for the period longer than female adults, but both couldn′t survive until 108 h.