Fruit preferences of Grapholitha molesta (Lepidoptera: Tortricidae) larvae and the primary sensory organ involved in fruit selection
中文摘要：
【目的】 明确梨小食心虫Grapholitha molesta（Busck）幼虫的寄主选择能力和主要感器。【方法】 在室内条件下，测定梨小食心虫幼虫在7种寄主果实、不同发育阶段果实及受损伤果实的上的数量，并测定3种感器单独、两两组合处理及3种感器全部处理后的幼虫在不同寄主果实上的数量。【结果】 1龄时，选择丰白毛桃、红富士苹果和霞光油桃的幼虫数分别为12.00、8.67 和9.00头，选择早酥梨、嘎啦苹果和皇冠梨的幼虫数为2.00、1.00、1.00 头；5龄时，选择上述6种果实的幼虫数依次为8.67、7.00、6.00、5.33、4.00和3.67头。选择丰白毛桃、红富士苹果和霞光油桃成熟期果实的幼虫数均显著高于选择同种未成熟和成熟早期果实。选择受损伤丰白毛桃、红富士苹果和霞光油桃的幼虫数显著高于选择同种未受损伤果实。分别单独处理触角、下颚须+下唇须和胸足的幼虫，未选择寄主果实的幼虫数为7.33-10.00头；两两感器组合处理后，未选择的幼虫数与单独处理触角无显著差异；3种感器全部处理的幼虫无选择能力，未选择的幼虫数为17.67头。【结论】 梨小食心虫幼虫可选择寄主，且对寄主的选择性随幼虫龄期增加而变化。梨小食心虫幼虫触角是其选择寄主果实的主要感器。
英文摘要：
[Objectives] Fruit preferences and the primary sensory organ used by Grapholitha molesta larvae to select fruit were identified. [Methods] The number of G. molesta larvae of different instars found on different fruits, and the number of different developmental stages found on the same fruit, and on cut fruits, were recorded and compared. We also compared the numbers of larvae that had had one, two, or all three, sensory organs, experimentally inactivated, on different fruits under laboratory conditions. [Results] Numbers of first instar larvae on Fengbai peach, Fuji apple, Xiaguang nectarine were 12.00, 8.67 and 9.00, respectively, and numbers on Zaosu pear, Gala apple and Huangguan pear were 2.00, 1.00 and 1.00, respectively. The number of fifth instar larvae on Fengbai peach, Fuji apple, Xiaguang nectarine, Zaosu pear, Gala apple and Huangguan pear was 8.67, 7.00, 6.00, 5.33, 4.00 and 3.67, respectively. The number of larvae found on mature Fengbai peach, Xiaguang nectarine, Fuji apple was significantly higher than that found on immature or early mature fruit. The number of larvae on cut Fengbai peach, Xiaguang nectarine and Fuji apple was significantly higher than that on uncut fruit. 7.33-10.00 larvae that had a single antennae, labial palpus+ maxillary palp or thoracic legs experimentally inactivated, no longer displayed any preference for specific fruits. There was no difference in the number of unselective larvae that had had two kinds of sensory organs inactivated and those that had had only their antennae inactivated. 17.67 larvae that had had all three sensory organs inactivated could not select host fruits. [Conclusion] G. molesta larvae have the ability to select host fruits, and this ability changes with larval development. The antennae are the most important sensory organ used in host fruit selection.