苹果全爪螨实验种群的密度效应研究

Study on Density-Dependent Effects of the Experimental Population of Panonychus ulmi

研究了苹果全爪螨实验种群的密度效应。实验结果表明:二斑叶螨卵期不存在密度效应;幼、若螨期间存在密度效应,幼、若螨密度与其成活率明显相关,幼、若螨初始密度的增加导致死亡率增加,并且当代性比向偏雌性方向发展,而子代性比向偏雄性方向发展;不同幼、若螨密度和成螨密度对成螨产卵量均有极显著差异。苹果叶片上螨口密度大于2.5～3.5头/cm2时,扩散量明显增加。

The effects of density-dependence on the experimental population ofPanonychus ulmi was studied. There was no density dependent effect in egg period. The density of larva and nymph had significant effect on the survival rate. With the rising of initial density of larva, the rate of death increased and the offsprings of present generation tended to have more female adults in sex ratio, but the offsprings of filial generation tended to have more male adults. The density changes of larva and adults led to obvious differences in fecundity. If the density of adults surpassed 2.5-3.5 per square centimeter in apple leave, the dispersal increased clearly.