Data from: Plasmodium infection brings forward mosquito oviposition

Invertebrate hosts often bring forward their reproductive effort in response to a parasitic infection. This is widely interpreted as a host-driven response aimed at compensating for the expected losses in future fitness as a result of parasitism. Here we report that mosquitoes bring forward their oviposition schedule when they are infected with Plasmodium, a parasite known to severely curtail mosquito fecundity. This response could aim at compensating for a negative time-dependent effect of the parasite on mosquito fitness, as infected mosquitoes seem to display a strong and progressive decrease in the quality of the eggs they lay. In addition, we show that this shift in oviposition date is dependent on mosquito strain: a comparison of several isogenic insecticide-susceptible and resistant mosquito strains reveals that only the former shift their oviposition strategy when infected. This pattern is consistent with the existence of a costly host-driven response to parasitism, as insecticide resistant mosquitoes have been shown to be in generally poorer condition.

无脊椎动物宿主在受到寄生虫感染时，通常会提前启动自身的生殖投入。该现象普遍被解读为宿主主动发起的应对策略，用以弥补寄生作用导致的未来适合度预期损失。本研究发现，蚊子感染疟原虫（Plasmodium）后会提前产卵时序；已知该寄生虫会严重削弱蚊子的繁殖力。此类响应或旨在抵消寄生虫对蚊子适合度产生的随时间累积的负面影响——受感染蚊子所产卵的质量会呈现显著且进行性的下降。此外，本研究证实产卵时序的调整与否取决于蚊子品系：通过对多组同基因杀虫剂敏感型与抗药性蚊子品系的对比分析发现，仅杀虫剂敏感型品系在感染后会调整其产卵策略。这一模式与“宿主针对寄生作用发起的响应存在适合度成本”的推论相符，因为已有研究表明抗药性蚊子的整体健康状况普遍较差。