The convergent lady beetle, Hippodamia convergens Guerin-Meneville, is a specialized predator of cereal aphids on the High Plains, completing its first generation each year in winter wheat, the resulting adults dispersing into summer crops and producing additional generations, contingent on the availability of aphids. In the present study, we tested the collective value of supplementary plant resources (sugars, pollen, and seedling wheat leaves), and small amounts of alternative prey, eggs of Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae), all provided together, for improving beetle life history and reproductive success even when suitable prey, Schizaphis graminum (Rondani) (Hemiptera: Aphididae), were provided ad libitum. Although a monotypic diet of S. graminum yielded slightly faster larval development and heavier adults than the omnivorous diet, preoviposition periods were extended and 21-d fecundities greatly reduced when this diet was continued through adult life, largely due to fewer oviposition days, although egg fertility was unaffected. The results highlight the critical importance of plant-derived resources even when suitable prey are not limiting. However, monotypic diet beetles that diapaused for 21 d in the presence of supplementary plant resources, plus moth eggs, achieved the same reproductive success as those reared on the omnivorous diet, with or without diapause, demonstrating that access to these resources post-emergence was sufficient to compensate for their absence during development. The diapause treatment itself had no impact on the fitness of beetles reared on the omnivorous diet, likely because neither its duration, nor the caloric restriction imposed, were sufficient to diminish reproductive effort.

中文翻译：

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杂食对特殊蚜虫捕食者的繁殖和生活史的好处，Hippodamia converens（鞘翅目：瓢虫科）

收敛的瓢虫，Hippodamia 收敛 Guerin-Meneville，是高平原谷物蚜虫的专门捕食者，每年在冬小麦中完成第一代，由此产生的成虫分散到夏季作物中并产生更多的世代，这取决于可用蚜虫。在本研究中，我们测试了补充植物资源（糖、花粉和小麦幼苗叶子）和少量替代猎物、Ephestia kuehniella（Zeller）（鳞翅目：Pyralidae）的卵的集体价值，所有这些都一起提供，用于即使在随意提供合适的猎物 Schizaphis graminum (Rondani) (Hemiptera: Aphididae) 的情况下，也能改善甲虫的生活史和繁殖成功率。尽管 S. 与杂食性饮食相比，禾本科的幼虫发育略快，成虫较重，当这种饮食持续到成年生活时，产卵前期延长，21 天的繁殖力大大降低，这主要是由于产卵天数减少，尽管卵子生育力不受影响。结果强调了植物源性资源的重要性，即使合适的猎物不受限制。然而，在补充植物资源和蛾卵存在下滞育 21 天的单型饮食甲虫，无论有没有滞育，都取得了与杂食性饮食饲养的相同的繁殖成功，这表明在出现后获得这些资源是足以弥补他们在开发过程中的缺席。