Tigreros Natasha, Norris Rachel H, Wang Eugenia H, Thaler Jennifer S
Department of Entomology, Cornell University, Ithaca, NY, 12854, USA.
Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 12854, USA.
Ecol Lett. 2017 Apr;20(4):487-494. doi: 10.1111/ele.12752. Epub 2017 Mar 10.
Theory on condition-dependent risk-taking indicates that when prey are in poor condition, their anti-predator responses should be weak. However, variation in responses resulting from differences in condition is generally considered an incidental by-product of organisms living in a heterogeneous environment. Using Leptinotarsa decemlineata beetles and stinkbug (Podisus maculiventris) predators, we hypothesised that in response to predation risk, parents improve larval nutritional condition and expression of anti-predator responses by promoting intraclutch cannibalism. We showed that mothers experiencing predation risk increase production of unviable trophic eggs, which assures provisioning of an egg meal to the newly hatched offspring. Next, we experimentally demonstrated that egg cannibalism reduces L. decemlineata vulnerability to predation by improving larval nutritional condition and expression of anti-predator responses. Intraclutch cannibalism in herbivorous insects might be a ubiquitous strategy, aimed to overcome the dual challenge of feeding on protein-limited diets while living under constant predation threat.
条件依赖型冒险理论表明，当猎物状态不佳时，它们的反捕食反应应该较弱。然而，因状态差异导致的反应变化通常被认为是生物体生活在异质环境中的一种偶然副产物。我们以马铃薯甲虫和猎蝽（黄斑蝽）为研究对象，假设在面对捕食风险时，亲代会通过促进窝内同类相食来改善幼虫的营养状况并增强反捕食反应。我们发现，经历捕食风险的雌虫会增加不可育营养卵的产出，从而确保为新孵化的后代提供卵类食物。接下来，我们通过实验证明，卵食行为通过改善幼虫营养状况和增强反捕食反应，降低了马铃薯甲虫被捕食的易感性。植食性昆虫的窝内同类相食可能是一种普遍存在的策略，旨在应对以蛋白质含量有限的食物为食且长期面临捕食威胁这一双重挑战。
