Crowdsourced online images provide insights into predator-prey interactions of putative natural enemies

Abstract

Most megadiverse clades of insects are herbivores, but several large radiations consist almost entirely of predators. Their species numbers make comprehensive direct observations of predator-prey interactions difficult to obtain. Citizen science approaches are increasingly utilized to harvest ecological data for organisms including insects. We use crowdsourced images documenting predator-prey interactions of assassin bugs (Hemiptera: Reduviidae), a speciose clade of predatory insects, to (1) determine the breakdown of assembled online images by geographic region and reduviid subfamily; (2) evaluate if the accumulated images provide new insights into prey diversity; and (3) assess evidence for taxa that feed on pest species, pollinators, and engage in intraguild predation. Photographs were assembled (n = 832) and resulted in an image database that included representatives of 11 subfamilies; most records belonged to diurnal Harpactorinae and Phymatinae, but some subfamilies with poorly understood prey diversity were also documented. Taxa with substantial image representation of prey (21–242 predation events) showed significant overlap with prey reported in the literature. A high percentage of images for Apiomerus Hahn and Phymata Latreille documented predation events on native and non-native bees; percentages varied widely among species of Zelus Fabricius. Arilus cristatus (Linnaeus) was documented to prey on several pest species, with little evidence for pollinator predation. Potential effects of these natural enemies on pollinators and intraguild predators should be further investigated, providing important insights into mechanisms influencing community structure and ecosystems processes.