Institute of Applied Ecology and Research Centre for Biodiversity and Eco-Safety, Fujian Agriculture and Forestry University, Fuzhou, China.
State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fuzhou, China.
Sci Rep. 2017 Feb 23;7:42636. doi: 10.1038/srep42636.
Intra-guild predation (IGP) is an important phenomenon structuring ecological communities and affects the success of biological control. Here we show that parasitism by the koinobiont wasp Cotesia vestalis is associated with behavioural changes in its larval host (diamondback moth, Plutella xylostella) that reduce risk of IGP. Compared with unparasitised caterpillars, parasitised P. xylostella moved less frequently to new feeding patches on plants and were less likely to fall from the plant. Wolf spiders killed significantly fewer parasitised larvae. Reflecting their reduced movement and capacity to select plant tissue of optimal quality, parasitised caterpillars fed at a lower rate and exhibited delayed development suggesting a trade-off between IGP avoidance and nutrient intake by the host. This change in behaviour to reduce risk may cascade to the first trophic level and help explain the stability of IGP systems.
种内捕食（IGP）是一种重要的生态群落结构现象，会影响生物防治的成功。在这里，我们表明，共生蜂 Cotesia vestalis 的寄生与幼虫宿主（小菜蛾，Plutella xylostella）的行为变化有关，这些变化降低了 IGP 的风险。与未被寄生的毛虫相比，被寄生的 P. xylostella 在植物上新觅食斑块上的移动频率较低，从植物上掉落的可能性也较小。狼蛛杀死的被寄生幼虫明显较少。这反映了它们减少的运动能力和选择最佳质量植物组织的能力，被寄生的毛虫进食速度较慢，发育延迟，表明宿主在避免种内捕食和摄入营养之间存在权衡。这种降低风险的行为变化可能会级联到第一营养级，并有助于解释 IGP 系统的稳定性。
