烟粉虱天敌日本刀角瓢虫的捕食行为

研究了日本刀角瓢虫雌成虫和幼虫捕食粉虱时的各种行为时间分配.结果表明,日本刀角瓢虫成虫的捕食行为可分为爬行、取食、清洁、静息、整翅和排泄6个部分.饥饿后的日本刀角瓢虫幼虫捕食烟粉虱卵时,幼虫各龄期间的取食和爬行时间无显著差异,对烟粉虱卵的处置时间随瓢虫幼虫虫龄的增大而缩短.日本刀角瓢虫雌成虫捕食烟粉虱卵时,饥饿后的雌成虫用于取食的时间显著长于非饥饿的雌成虫,而用于清洁、静息和爬行的时间显著短于非饥饿的雌成虫;饥饿后的瓢虫雌成虫对卵的处置时间显著长于非饥饿的雌成虫.饥饿后的日本刀角瓢虫雌成虫捕食烟粉虱若虫时,瓢虫雌成虫的取食时间随烟粉虱若虫虫龄的增大而增加,清洁和静息时间随烟粉虱若虫虫龄的增大而缩短,对若虫的处置时间随烟粉虱若虫虫龄的增大而增加.

Feeding behavior of Serangium japonicum (Coleoptera:Coccinellidae),a predator of Bemisia tabaci (Homoptera:Aleyrodidae)

Serangiurm japonicum is an important predator of whiteflies in China. In this study, the Bemisia tabaci-attacking behavior of S. japonicum adults and larvae was observed by a videocassette recorder. The results showed that the predatory behavior of S. japonicum adults was characteristic with six events, i.e., walking, feeding, clearing, resting, vibrating wings, and excreting. The starved larvae of S. japonicum was fond spending all times in feeding and walking on host eggs, with no time in resting or clearing throughout the process. The time included in feeding and walking was not significant different among different instars of S. japonicum. The handing time per egg decreased with S. japonicum larvae developed from instar I to IV, but differed little between instar III and IV. The starved females of S. japonicum spent longer time on egg feeding, but less time on clearing, resting and walking than satiated females. The time for starved female to predate on B. tabaci nymphs and pupae increased as the host nymphs developed.