越冬代梨木虱、梨二叉蚜产卵选择对子代种间竞争的影响

梨树萌芽期，越冬代梨木虱Cacopsylla chinensis和梨二叉蚜Schizaphis piricola子代共用同一食物资源，为了解其母代如何避免子代发生种间竞争，通过研究其产卵特点表明，梨二叉蚜和梨木虱在梨树枝条上的产卵位点不同。梨木虱主要在花芽枝上进行产卵，偏好于花芽芽鳞和枝条基部刻痕处产卵，以枝条基部产卵量最多，其次为顶花芽，产卵量随芽位次序依次下降，梨木虱还可在叶芽部位产卵，但数量较少；梨二叉蚜主要于叶芽枝上进行产卵，偏好在叶芽枝的第2、3芽位产卵，顶芽和枝条基部无产卵，未见梨二叉蚜在花芽部位产卵；在花芽枝上，梨木虱卵的空间生态位大于梨二叉蚜、叶芽枝上却相反，两者在梨树枝条上的产卵空间生态位呈分离状态；梨木虱和梨二叉蚜孵化的若虫数量及空间分布特点与卵一致；对梨木虱和梨二叉蚜产卵位点分析表明，其产卵位点的物理性状明显不同。本研究明确了梨木虱和梨二叉蚜母代通过不同产卵位点的选择，降低了子代种间的同位竞争。

Effects of oviposition selection of maternal generation on the interspecific competition in the same position between pear psylla and pear aphid offspring

The offspring of overwintering generation pear psylla Cacopsylla chinensis and pear aphid Schizaphis piricola share the same food resource during pear sprouting time. In order to understand how to alleviate this competition, we researched the oviposition choice characteristics of overwintering pear psylla and pear aphid maternal generation, results showed that the oviposition sites of pear psylla and pear aphid on the pear branches were differently. Pear psylla preferred flower bud branch as oviposition sites, pear psylla mainly oviposit on the flower bud scales and the base nicks of pear branch. The branch base had the largest number of eggs, followed by the top flower bud and the number of eggs declined with the order of flower buds. In addition, pear psylla can lay few eggs on the leaf buds. Pear aphid mainly oviposit on the leaf bud branches, preferred to lay eggs on the 2nd and 3rd leaf buds and no egg was found at the base of the branch and flower buds; The spatial niche width of pear psylla''s eggs on the flower bud branch was larger than pear aphid, but turn on opposite on the leaf bud branch, both the overlap spatial niches index between pear psylla and pear aphid in flower bud branch and leaf bud branch were lower; The number and spatial distribution characteristics of pear psylla and pear aphid nymphs were consistent with the their eggs distribution; To analysis the egg laying sites of pear psylla and pear aphid which displayed the different physical characteristics. This study clarified that the maternal generation of pear psylla and pear aphid could reduce the interspecific competition among the offspring on the same feeding position through the selection of different oviposition sites.