State Key Laboratory to Efficient Production of Forest Resources, Beijing Forestry University, Beijing, China.
Beijing Key Laboratory for Forest Pest Control, Beijing Forestry University, Beijing, China.
Pest Manag Sci. 2024 Nov;80(11):5656-5671. doi: 10.1002/ps.8282. Epub 2024 Jul 9.
Monochamus saltuarius is a destructive trunk-borer of pine forest and an effective dispersal vector for pinewood nematode (PWN), a causative agent of pine wilt disease (PWD), which leads to major ecological disasters. Cold winter temperatures determine insect survival and distribution. However, little is known about the cold tolerance and potential physiological mechanisms of M. saltuarius.
We demonstrated that dead Pinus koraiensis trunks do not provide larvae with insulation. The M. saltuarius larvae are freeze-tolerant species. Unlike most other freeze-tolerant insects, they can actively freeze extracellular fluid at higher subzero temperatures by increasing their supercooling points. The main energy sources for larvae overwintering are glycogen and the mid-late switch to lipid. The water balance showed a decrease in free and an increase in bound water of small magnitude. Cold stress promoted lipid peroxidation, thus activating the antioxidant system to prevent cold-induced oxidative damage. We found eight main pathways linked to cold stress and 39 important metabolites, ten of which are cryoprotectants, including maltose, UDP-glucose, d-fructose 6P, galactinol, dulcitol, inositol, sorbitol, l-methionine, sarcosine, and d-proline. The M. saltuarius larvae engage in a dual respiration process involving both anaerobic and aerobic pathways when their bodily fluids freeze. Cysteine and methionine metabolism, as well as alanine, aspartate, and glutamate metabolism, are the most important pathways linked to antioxidation and energy production.
The implications of our findings may help strengthen and supplement the management strategies for monitoring, quarantine, and control of this pest, thereby contributing to controlling the further spread of PWD. © 2024 Society of Chemical Industry.
松墨天牛是松林的破坏性蛀干害虫，也是松材线虫（PWN）的有效传播媒介，松材线虫是松材萎蔫病（PWD）的病原体，导致重大生态灾难。寒冷的冬季温度决定了昆虫的生存和分布。然而，对于松墨天牛的耐寒性和潜在生理机制知之甚少。
我们证明了死亡的红松树干并不能为幼虫提供绝缘。松墨天牛幼虫是耐寒物种。与大多数其他耐寒昆虫不同，它们可以通过提高过冷点来主动将细胞外液在更高的亚零温度下冻结。幼虫越冬的主要能量来源是糖原，从中期到后期转变为脂质。水平衡显示自由水减少，结合水略有增加。冷应激促进脂质过氧化，从而激活抗氧化系统以防止冷诱导的氧化损伤。我们发现了与冷应激相关的 8 条主要途径和 39 个重要代谢物，其中 10 个是冷冻保护剂，包括麦芽糖、UDP-葡萄糖、d-果糖 6P、半乳糖醇、山梨醇、肌醇、甘露醇、l-蛋氨酸、肌氨酸和 D-脯氨酸。当松墨天牛幼虫的体液冻结时，它们会进行涉及无氧和有氧途径的双重呼吸过程。半胱氨酸和蛋氨酸代谢以及丙氨酸、天冬氨酸和谷氨酸代谢是与抗氧化和能量产生最相关的最重要途径。
我们的研究结果可能有助于加强和补充对这种害虫的监测、检疫和控制管理策略，从而有助于控制 PWD 的进一步传播。© 2024 化学工业协会。
