Department of Entomology, Beijing Forestry University, Haidian District, Beijing 100083, China.
Department of Forestry Engineering, Guangxi Eco-engineering Vocational and Technical College, Guangxi Zhuang Autonomous Region 545004, China.
Environ Entomol. 2021 Oct 12;50(5):1166-1172. doi: 10.1093/ee/nvab078.
Dormancy is important for overwintering insects to resist and adapt to adverse conditions. Dormancy generally contains quiescence and diapause. Eucryptorrhynchus brandti Harold (Coleoptera: Curculionidae), tree-of-heaven trunk weevil (TTW), is a destructive pest and highly host-specific to Ailanthus altissima in China. TTW has one generation per year and overwinters as both larvae and adults. In this study, to examined dormancy type of adults and find a method to store overwintering adults, we collected adults from 20 October 2018 to 13 March 2019. We studied the behavior and reproductive development of adults under field cold conditions for 0 and 10 d and laboratory warm conditions for 5 and 10 d. We recorded developing eggs in females, and the clarity of the testis edge, the yellow point in the testis lobe, the ratio of the inner content in the accessory gland, and the accessory gland color in males. Adults transferred from the field to the laboratory had resumed reproductive development directly. Results indicated that the dormancy type of TTW adults was quiescence. Adults stored in the field were still in a dormant state and the field-storage method was effective. Current study provided basic data for controlling overwintering TTW adults and solve the storage of insect sources during the winter.
休眠对于越冬昆虫抵抗和适应不利条件非常重要。休眠通常包含静止和滞育。臭椿沟眶象（Eucryptorrhynchus brandti Harold）（鞘翅目：象甲科），是一种具有破坏性的害虫，在中国对臭椿具有高度的专食性。臭椿沟眶象每年发生一代，以幼虫和成虫越冬。在这项研究中，为了研究成虫的休眠类型并找到一种储存越冬成虫的方法，我们于 2018 年 10 月 20 日至 2019 年 3 月 13 日期间采集了成虫。我们研究了野外寒冷条件下成虫的行为和生殖发育，持续 0 和 10 天；以及实验室温暖条件下 5 和 10 天的情况。我们记录了雌性中发育的卵子，以及雄性中睾丸边缘的清晰度、睾丸叶中的黄色点、附属腺内内容物的比例和附属腺的颜色。从野外转移到实验室的成虫直接恢复了生殖发育。结果表明，臭椿沟眶象成虫的休眠类型为静止休眠。野外储存的成虫仍处于休眠状态，野外储存方法有效。本研究为控制越冬臭椿沟眶象成虫提供了基础数据，并解决了冬季昆虫来源储存的问题。
