Dynamics of macronutrient self-medication and illness-induced anorexia in virally-infected insects

1. Some animals change their feeding behaviour when infected with parasites, seeking out substances that enhance their ability to overcome infection. This “self-medication” is typically considered to involve the consumption of toxins, minerals or secondary compounds. However, recent studies have shown that macronutrients can influence the immune response, and that pathogen-challenged individuals can self-medicate by choosing a diet rich in protein and low in carbohydrates. Infected individuals might also reduce food intake when infected (i.e. illness-induced anorexia). 2. Here, we examine macronutrient self-medication and illness-induced anorexia in caterpillars of the African armyworm (Spodoptera exempta) by asking how individuals change their feeding decisions over the time course of infection with a baculovirus. We measured self-medication behaviour across several full-sib families to evaluate the plasticity of diet choice and underlying genetic variation. 3. Larvae restricted to die...

1. 部分动物在被寄生虫侵染后会改变其取食行为，主动搜寻能够提升自身抗感染能力的物质。这类"自我药疗（self-medication）"通常被认为是通过摄入毒素、矿物质或次生代谢产物实现。然而近期研究表明，宏量营养素可影响机体免疫应答，受病原体胁迫的个体可通过选择高蛋白、低碳水化合物的饮食完成自我药疗。受感染个体还可能在侵染后减少进食量（即疾病诱导的厌食症）。2. 本研究以非洲粘虫（Spodoptera exempta）幼虫为研究对象，探究其宏量营养素自我药疗与疾病诱导的厌食症行为，通过分析个体在被杆状病毒（baculovirus）侵染后的取食决策随时间进程的变化展开研究。我们对多个全同胞家系的自我药疗行为进行了测定，以评估取食选择的可塑性及其潜在的遗传变异。3. 被限制取食的幼虫……