矢尖蚧的重要天敌二双斑唇瓢虫的研究

A LIFE HISTORY STUDY OF CHILOCORUS BIJUGUS [COL.: COCCINELLIDAE], AN IMPORTANT PREDATOR OF THE ARROWHEAD SCALE IN GUIZHOU

二双斑唇瓢虫是多种果树蚧类的重要捕食性天敌之一。该虫在贵阳一年发生4代,世代重叠。单雌产卵量平均为94.41粒,最多465粒。成虫寿命平均为124.71天,最多222天。该虫与矢尖蚧的发生期较为一致,能在柑桔园中形成比较稳定的种群,对矢尖蚧种群有较大的控制作用,田间对矢尖蚧的捕食率以8,9月间为最高,可达48.85％。

Results of the outdoor studies during 1985-87 indicated that the ladybird beetle, Chilocorus bijugus, had four overlapping generations in a year in Guiyang, Guizhou Province (South west of China). In laboratory rearings at 25℃the average fecundity of the predator was found to be 94.4 eggs per female, with the maximum of 465 eggs. The average adult longevity was 124.7 days, maximum 222 days. The phenology of C. bijugus was well synchronized with that of Unaspis yanonensis. The predator formed steady populations in the citrus groves, playing an important role in controlling the scale populations. The highest preying rate of the predator on the scale was 48.8%, occurred during August and September of a year.