果实种类及发育阶段对梨小食心虫幼虫钻蛀率和蛹重的影响

【目的】明确梨小食心虫Grapholitha molesta在寄主果实上的钻蛀率和蛹重与寄主种类和果实发育阶段的关系，为其田间预测预报和综合防控提供技术依据。【方法】在室内条件下测定了接卵后72 h梨小食心虫初孵幼虫在不同发育阶段的3个种共6个品种水果［苹果Malus pumila (嘎啦苹果), 桃Amygdalus persica (大久保毛桃、丰白毛桃和霞光油桃), 梨Pyrus bretschneideri (砀山酥梨和玉露香梨)］果实上的钻蛀率以及在不同果实状态的4个水果品种(大久保毛桃、丰白毛桃、砀山酥梨和玉露香梨)果实上72 h的钻蛀率；比较了接卵后24 h和72 h初孵幼虫在不同发育阶段的3个苹果品种(嘎啦苹果、富士苹果和金冠苹果)果实上的钻蛀率；并测定了不同发育阶段的金冠苹果、富士苹果、嘎啦苹果、砀山酥梨和丰白毛桃上的梨小食心虫蛹重。【结果】接卵后72 h梨小食心虫初孵幼虫在6个不同水果品种果实上的钻蛀率从高到低依次为：霞光油桃＞嘎啦苹果＞砀山酥梨＞玉露香梨＞大久保毛桃＞丰白毛桃；除霞光油桃外，其他5个水果品种果实的发育阶段显著影响初孵幼虫钻蛀率。对于嘎啦苹果，接卵后72 h初孵幼虫在其幼果上的钻蛀率最高(73.69%)，在其着色期果实上钻蛀率最低(32.51%)；在大久保毛桃、丰白毛桃、砀山酥梨和玉露香梨上，接卵后72 h初孵幼虫的钻蛀率均随果实生长发育而增加。初孵幼虫在3 个苹果品种着色期和成熟期果实上的钻蛀率随处理时间的增加而显著下降，而在其幼果上变化不显著。寄主种类及其发育阶段也显著影响梨小食心虫蛹重，成熟毛桃和梨饲养的雌、雄蛹重显著高于未成熟果实饲养的蛹重，着色期苹果不利于蛹重的增加。【结论】果实种类及发育阶段显著影响梨小食心虫初孵幼虫钻蛀率和蛹重，取食成熟期梨和桃的梨小食心虫初孵幼虫钻蛀率和蛹重显著高于取食未成熟果实的个体。

Effects of fruit species and developmental stage on the larval boring rate and pupal weight of Grapholitha molesta (Lepidoptera: Tortricidae)

【Aim】 This study aims to clarify the relationship between the boring rate andpupal weight of the oriental fruit moth, Grapholitha molesta, on host fruits and hostspecies and fruit developmental stage, so as to provide the theoretical basis for itsprediction and control. 【Methods】 The boring rates of the newly hatched larvae of G.molesta on fruits of six varieties of three fruit species ［Malus pumila (variety Galaapple), Amygdalus persica (varieties Dajiubao peach, Fengbai peach and Xiaguang nectarine),Pyrus bretschneideri (varieties Dangshan pear and Yuluxiang pear)］ at differentdevelopmental stages and on four fruit varieties (Dajiubao peach, Fengbai peach, Dangshanpear and Yuluxiang pear) with different fruit statuses at 72 h post inoculating eggs weredetermined in the laboratory. The boring rates of the newly hatched larvae on differentapple varieties (Gala apple, Fuji apple and Golden delicious apple) at different developmental stages at 24 h and 72 h post inoculating eggs were compared. The pupal weightof G. molesta on Golden delicious apple, Fuji apple, Gala apple, Dangshan pear and Fengbaipeach at different developmental stages were also determined. 【Results】 The boring rateof the newly hatched larvae of G. molesta at 72 h post inoculating eggs was the highest onXiaguang nectarine, followed by on Gala apple, Dangshan pear, Yuluxiang pear, Dajiubaopeach and Fengbai peach. Except Xiaguang nectarine, the developmental stage of the otherfive fruits significantly affected the boring rate of the newly hatched larvae. The boringrates of the newly hatched larvae at 72 h post inoculating eggs were 73.69% and 32.51% onyoung fruit and coloring fruit of Gala apple, respectively. The boring rates of the newlyhatched larvae on Dajiubao peach, Fengbai peach, Dangshan pear and Yuluxiang pear at 72 hpost inoculating eggs increased with the developmental stage of host fruits. The boringrates of the newly hatched larvae on the coloring fruits and mature fruits of three applevarieties significantly reduced with treatment time, but the boring rates on young fruitsshowed no significant change. Meanwhile, the host species and their developmental stagealso affected the pupal weight of G. molesta, the female and male pupal weight of G. molesta on mature peach and pear were significantly higher than those on immature ones, andcoloring apples are unsuitable to the female and male pupal weight of G. molesta.【Conclusion】 Fruit species and developmental stage significantly affect the boring rate of the newly hatched larvae and the pupal weight of G. molesta, and the boring rate of thenewly hatched larvae and the pupal weight of G. molesta on mature pear and peach aresignificantly higher than those on immature ones.