Abstract

The conditions of entomopathogen persistence in a host-insect organism and the mechanisms of their conversion to the acute form of infection is one of the most important questions for an understanding of epizootics functioning. Here, we estimate the dynamics of the physiological parameters of the gypsy moth (Lymantria dispar L.) responsible for insect protection from antivirals under stress (starvation) and their correlation with the activation of the latent form of L. dispar, multiple nucleopolyhedrosis. We find that starvation leads to an increase in the dopamine concentration in the larval hemolymph and a decrease in the total number of hemocytes, which is associated with the high necrotic cell death. The number of viral carriers in the studied population and their activation level with starvation are estimated to be more than 70%. Polymerase chain reaction analysis showed an increase in the number of virus-positive individuals starting from the first day of starvation. At the same time, the nonspecific mortality of insects began only after 7 days of starvation, whereas the mortality from an activated virus began after 2–3 days of starvation. Thus, we show that at high insect-population density, a lack of food resources plays the leading role in the activation of the covert form of baculovirus infection. When analyzing the dynamics of physiological parameters, we assume that the conversion of a covert baculovirus form into an acute infection can be triggered by necrotic processes induced by starvation.

中文翻译：

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饥饿作为种群应激因素对吉普赛蛾隐蔽杆状病毒感染激活的影响

摘要

宿主病原生物中昆虫病原体持续存在的条件及其转化为急性感染形式的机制是了解动物流行病功能的最重要问题之一。在这里，我们估算了吉普赛蛾（Lymantria dispar L.）的生理参数的动态变化，该生理参数负责在压力（饥饿）下抵抗抗病毒药的昆虫保护，以及它们与潜在形式的L. dispar的激活的相关性，多核多角体病。我们发现饥饿导致幼虫血淋巴中多巴胺浓度的增加和血细胞总数的减少，这与高坏死细胞死亡有关。研究人群中病毒携带者的数量及其在饥饿状态下的激活水平估计超过70％。聚合酶链反应分析显示，从饥饿的第一天开始，病毒阳性个体的数量增加。同时，昆虫的非特异性死亡仅在饥饿7天后开始，而活化病毒的死亡则在饥饿2至3天后开始。因此，我们表明在高昆虫种群密度下，食物资源的缺乏在杆状病毒感染的隐蔽形式的激活中起着主导作用。