Marques Renata Vieira, Sarmento Renato Almeida, Oliveira Adriana Gonçalves, Rodrigues Diego de Macedo, Venzon Madelaine, Pedro-Neto Marçal, Pallini Angelo, Janssen Arne
Department of Entomology Federal University of Viçosa Viçosa Minas Gerais Brazil.
Federal University of Tocantins (UFT) Gurupi Tocantins Brazil.
Ecol Evol. 2018 Jun 11;8(14):6952-6964. doi: 10.1002/ece3.4211. eCollection 2018 Jul.
Intraguild predation is a mix of competition and predation and occurs when one species feeds on another species that uses similar resources. Theory predicts that intraguild predation hampers coexistence of species involved, but it is common in nature. It has been suggested that increasing habitat complexity and the presence of alternative food may promote coexistence. Reciprocal intraguild predation limits possibilities for coexistence even further. Habitat complexity and the presence of alternative food are believed to promote coexistence. We investigated this using two species of predatory mites, and , by assessing co-occurrence in the field and on arenas differing in spatial structure in the laboratory. The predators co-occured on the same plants in the field. In the laboratory, adults of the two mites fed on juveniles of the other species, both in the presence and the absence of a shared food source, showing that the two species are involved in reciprocal intraguild predation. Adults of also attacked adults of . This suggests limited possibilities for coexistence of the two species. Indeed, invariably went extinct extremely rapidly on arenas without spatial structure with populations consisting of all stages of the two predators and with a shared resource. Coexistence was prolonged on host plant leaves with extra food sources, but still went extinct. On small, intact plants, coexistence of the two species was much longer, and ended with the other species, , often going extinct. These results suggest that spatial structure and the presence of alternative food increase the coexistence period of intraguild predators.
集团内捕食是竞争与捕食的混合形式，当一个物种以利用相似资源的另一个物种为食时就会发生。理论预测集团内捕食会阻碍相关物种的共存，但在自然界中却很常见。有人提出增加栖息地复杂性和存在替代食物可能会促进共存。相互的集团内捕食会进一步限制共存的可能性。栖息地复杂性和替代食物的存在被认为会促进共存。我们通过评估田间以及实验室中空间结构不同的实验场地中的共存情况，使用两种捕食螨类物种 和 对此进行了研究。这两种捕食者在田间的同一植物上共存。在实验室中，无论是否存在共享食物源，两种螨类的成虫都会捕食另一种的若虫，这表明这两个物种参与了相互的集团内捕食。 的成虫也会攻击 的成虫。这表明这两个物种共存的可能性有限。确实，在没有空间结构、由两种捕食者的各个发育阶段组成且有共享资源的实验场地中， 总是极其迅速地灭绝。在有额外食物源的寄主植物叶片上，共存时间延长了，但 仍然灭绝了。在小型完整植物上，两个物种的共存时间长得多，并且以另一个物种 常常灭绝而告终。这些结果表明，空间结构和替代食物的存在会增加集团内捕食者的共存时间。
