红点唇瓢虫对杨圆蚧的捕食功能

Predatory Function of Chilocorus kuwanae Silvestri on Quadraspidiotus gigas (Thiem et Gerneck)

杨圆蚧是我国东北林区杨树的主要害虫，对它的防治已经由化学防治向生物防治转化，红点唇瓢虫作为杨圆蚧的主要捕食性天敌，对杨圆蚧有较好的控制作用。在前人研究的基础上〔１～３〕，经在黑龙江省大庆市观察，越冬后的成瓢和各龄幼瓢，在林间除掉跳小蜂情况下，应用Ｈｏｌｉｎｇ圆盘公式Ⅱ型计算日极限捕蚧量：成瓢为１８．４１头／日，Ⅰ，Ⅱ，Ⅲ，Ⅳ，Ⅴ龄分别为１．６７７６头／日、２．０８８０头／日、６．１７６７头／日、１９．３００８头／日、３１．３４８０头／日；当幼瓢在林间被跳小蜂寄生时，应用Ｈｏｌｉｎｇ圆盘公式Ⅲ型计算各龄幼瓢日极限捕蚧量：Ⅰ，Ⅱ，Ⅲ，Ⅳ，Ⅴ龄幼虫分别为２．３８头／日、２．６２头／日、９．３３头／日、７．００３头／日、５．５９头／日。Ⅰ，Ⅱ级木各助迁一头越冬后的成瓢，在林间幼瓢被跳小蜂寄生情况下，杨圆蚧的虫口密度分别下降一个危害等级，控制力为５３．５％

- Quadraspidiotus gigas is a main pest infesting poplar in Northeast China. Chilocorus kuwanae, as a key nature enemy, has good control function to Quadraspidiotus gigas. Based on former researches and observations made in Daqing, Heilongjiang Province, the maximum pest amount predated by an adult and different instar larvae of ladybird per day were calculated with Holling-Ⅱ formula. Under the condition that all Homalotylus flaminius were eliminated, the insects predated by an adult, 1-, 2-, 3-, 4- and 5-instar larvae per day were 18.41, 1.6556, 2.0880, 6.1767, 19.3008 and 31.3480 respectively. When there existed parasitism of H. flaminius, calculated by Holling-Ⅲ formula, the maximum pest amount predated by 1-, 2-, 3-, 4- and 5-instar larvae per day were 2.38, 2.62, 9.33, 7.003 and 5.59 respectively. The artificial migration of one adult lady bird on trees of ⅠorⅡ infection grade reduced the population density of Quadraspidiotus gigas for one damage grade under the condition of parasitism of H. Flaminius on ladybird's larvae, and the natural control ability reached 53%.