龟纹瓢虫生物学特性及其对棉铃虫捕食功能的研究

Studies on Biological Characteristics of Propylea japonica and ItsPredation Function to Helicoverpa armigera

研究结果表明，龟纹瓢虫近年来田间发生量逐年增多，１９９４年６月中下旬至７月初百株累计虫量最高可达６０４头，占天敌总发生量的８９．５％，这段时间恰与二代棉铃虫发生盛期相吻合。龟纹瓢虫成、幼虫虽喜食蚜虫，但此期田间蚜虫发生量甚少，故对棉铃虫有一定控制作用，其捕食量随幼虫龄期及猎物密度增高而增多．温度１５～３５℃范围内均能正常生长发育，但发育历期随温度升高而缩短，捕食量也随温度升高而增多，捕食功能反应符合Ｈｏｌｌｉｎｇ（１９５９）Ⅱ型反应，故可用圆盘方程拟合。对于龟纹瓢虫更深一步研究，可进一步为棉铃虫综合防治提供理论依据。

The population of thunberg(Propylea japonica),one of the principal preda-ceous species in cotton fields,was increased during 1991～1994,and reached a record ofaccumulative number of 604 per hundred cotton plants from later June to early July in1994.The occurrence peak of thunberg coincided with that of bollworm(Helicoverpaarmigera)of second generation so it had scmecontrol effect on the later,during very lowpopulation of cotton aphis to which both adult and larvae of thunberg prefer.Thunberggrown and developed well under the temperature of 15～35℃,and with the increased tem-perature,its developmental duration shortened and its predating efficiency increased.Thepredated amount of bollworm by thumberg increased with increased larvae instars of thum- berg and bollworm densities. The functional response fitted Holling’s predation responseequation II,and could be fit with the Disk Equation.