Zhang Dao-Wei, Xiao Zhong-Jiu, Zeng Bo-Ping, Li Kun, Tang Yan-Long
School of Biological and Agricultural Science and Technology, Zunyi Normal University, Zunyi, China.
Front Physiol. 2019 Mar 5;10:163. doi: 10.3389/fphys.2019.00163. eCollection 2019.
Intermittent food shortages are commonly encountered in the wild. During winter or starvation stress, mammals often choose to hibernate while insects-in the form of eggs, mature larvae, pupae, or adults opt to enter diapause. In response to food shortages, insects may try to find sufficient food to maintain normal growth and metabolism through distribution of populations or even migration. In the face of hunger or starvation, insect responses can include changes in behavior and/or maintenance of a low metabolic rate through physiological adaptations or regulation. For instance, in order to maintain homeostasis of the blood sugar, trehalose under starvation stress, other sugars can be transformed to sustain basic energy metabolism. Furthermore, as the severity of starvation increases, lipids (especially triglycerides) are broken down to improve hunger resistance. Starvation stress simultaneously initiates a series of neural signals and hormone regulation processes in insects. These processes involve neurons or neuropeptides, immunity-related genes, levels of autophagy, heat shock proteins and juvenile hormone levels which maintain lower levels of physiological metabolic activity. This work focuses on hunger stress in insects and reviews its effects on behavior, energy reserve utilization, and physiological regulation. In summary, we highlight the diversity in adaptive strategies of insects to hunger stress and provides potential ideas to improve hunger resistance and cold storage development of natural enemy insects. This gist of literature on insects also broadens our understanding of the factors that dictate phenotypic plasticity in adjusting development and life histories around nutritionally optimal environmental conditions.
在野外，间歇性食物短缺是常见现象。在冬季或饥饿胁迫期间，哺乳动物通常选择冬眠，而昆虫——以卵、成熟幼虫、蛹或成虫的形式——则选择进入滞育状态。为应对食物短缺，昆虫可能会通过种群扩散甚至迁移来寻找足够的食物以维持正常生长和新陈代谢。面对饥饿或饥荒，昆虫的反应可能包括行为改变和/或通过生理适应或调节来维持低代谢率。例如，为了维持血糖稳态，在饥饿胁迫下，海藻糖、其他糖类可以被转化以维持基本能量代谢。此外，随着饥饿程度的增加，脂质（尤其是甘油三酯）会被分解以提高抗饥饿能力。饥饿胁迫同时会在昆虫体内引发一系列神经信号和激素调节过程。这些过程涉及神经元或神经肽、免疫相关基因、自噬水平、热休克蛋白和保幼激素水平，从而维持较低水平的生理代谢活动。这项工作聚焦于昆虫的饥饿胁迫，并综述了其对行为、能量储备利用和生理调节的影响。总之，我们强调了昆虫对饥饿胁迫适应性策略的多样性，并为提高天敌昆虫的抗饥饿能力和冷藏发育提供了潜在思路。有关昆虫的这一文献要点也拓宽了我们对在营养最优环境条件下决定调节发育和生活史表型可塑性因素的理解。
