Borowczak Rudyard J, Wood Mary A, Bradshaw William E, Armbruster Peter A, Holzapfel Christina M
Institute of Ecology and Evolution University of Oregon Eugene Oregon USA.
Department of Biology Georgetown University Washington DC USA.
Ecol Evol. 2025 Apr 28;15(4):e71335. doi: 10.1002/ece3.71335. eCollection 2025 Apr.
Herein, we determine life-history consequences of selection on blood feeding in a polymorphic population of the pitcher-plant mosquito, Coq. (Diptera: Culicidae). All populations of produce an initial batch of eggs without ever taking a blood meal (biting); southern populations require a blood meal for the second and subsequent batches of eggs, but are polymorphic for propensity to bite. To determine correlated life-history responses to direct selection on blood feeding, we compared fecundity, adult longevity, and reproductive allocation between a line selected specifically for increased blood feeding and its unselected, control line maintained in parallel for 11 generations. Previous studies have focused on the fitness benefits of blood feeding in terms of overall fecundity. Herein, we evaluate a novel fitness benefit of blood feeding that reduces the risk of reproductive failure by spreading that risk across multiple reproductive events in a population confronted with an unpredictably variable larval environment. We propose that "spreading the risk" reinforces selection on blood feeding in other arthropods in which the separation of fecundity from reproductive allocation in time or space has previously been neglected. Importantly, heritable variation for "spreading the risk" should enhance vectorial capacity and make more difficult vector control through larval source reduction.
在此，我们确定了猪笼草蚊（Coq.，双翅目：蚊科）多态种群中选择吸食血液对生活史的影响。所有猪笼草蚊种群都会在从未吸食血液（叮咬）的情况下产出第一批卵；南方种群在产出第二批及后续批次的卵时需要吸食血液，但在叮咬倾向方面存在多态性。为了确定对吸食血液的直接选择所产生的相关生活史反应，我们比较了专门为增加吸食血液而选择的品系与其平行维持了11代的未选择对照品系之间的繁殖力、成虫寿命和生殖分配情况。先前的研究主要关注吸食血液在总体繁殖力方面的适应性益处。在此，我们评估了吸食血液的一种新的适应性益处，即在面对不可预测的多变幼虫环境的种群中，通过将风险分散到多个繁殖事件来降低繁殖失败的风险。我们提出，“分散风险”强化了对其他节肢动物吸食血液的选择，而在这些节肢动物中，繁殖力与生殖分配在时间或空间上的分离此前一直被忽视。重要的是，“分散风险”的可遗传变异应会增强媒介能力，并使通过减少幼虫来源进行媒介控制变得更加困难。
