Predators frequently compete with other species for prey but can also interact by preying on each other’s vulnerable stages. Because eggs and juveniles are more vulnerable to this intraguild predation than adults, their survival will depend on maternal strategies to reduce predation risk. Recently, we reported that adult female predatory mites Gynaeseius liturivorus Ehara (Acari: Phytoseiidae) reduce intraguild predation on their eggs by remaining at oviposition sites, thus deterring the egg predators. In addition, they avoid oviposition close to eggs laid by conspecific females. We therefore expected that adult female G. liturivorus protect their own eggs better against these egg predators than eggs of other females. This was tested using juveniles of the predatory mite Neoseiulus californicus McGregor (Acari: Phytoseiidae) as egg predators and the western flower thrips, Frankliniella occidentalis Pergande (Thysanoptera: Thripidae), as the shared prey. When G. liturivorus eggs were kept with their mothers, the presence of juvenile egg predators did not affect the survival of eggs. However, when G. liturivorus eggs were kept with females that were not their mothers, the mortality of eggs in the presence of juvenile egg predators increased. When adult female G. liturivorus were guarding their eggs, they killed a similar number of juvenile egg predators as females that were not kept with their eggs. Hence, adult female G. liturivorus protect their eggs by remaining close to their eggs.

中文翻译：

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掠食性螨虫保护自己的卵免受掠食者侵害

捕食者经常与其他物种争夺猎物，但也可以通过捕食彼此脆弱的阶段进行互动。由于卵和幼虫比成人更容易受到这种公会内捕食，因此它们的存活将取决于孕产妇减少捕食风险的策略。最近，我们报道了成年雌性掠食性螨Gynaeseius liturivorus Ehara（Acari：Phytoseiidae）通过留在产卵部位而减少了对公卵的公会捕食，从而阻止了食肉的食肉动物。此外，它们避免在同种雌性产卵附近产卵。因此，我们期望成年雌性斜纹夜蛾比其他雌性卵更好地保护自己的卵免受这些天敌。使用捕食性螨类的幼虫进行了测试食蟹新食蟹（Neoseiulus californicus McGregor）（Acari：Phytoseiidae）和西方花蓟马（Frankliniella occidentalis Pergande）（Thysanoptera：Thripidae）作为共同的猎物。当G. liturivorus卵与母亲一起饲养时，幼卵捕食者的存在不会影响卵的存活。但是，当将李氏梭菌卵与不是其母体的雌性一起饲养时，在存在幼虫捕食者的情况下，卵的死亡率增加。当成年雌性G. liturivorus保护卵子时，他们杀死了数量与不随卵饲养的雌性鱼类似数量的幼稚天敌。因此，成年雌性G. liturivorus 通过保持靠近卵来保护卵。