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Abstract :
[en] Exploiting the ecological networks formed by the interactions among aphids, their associated fungal pathogens, and predator fauna will give new insight for future efficient aphid control practices. Although aphid infestation in crops can be effectively controlled by either predatory ground beetles, hoverflies or entomopathogenic fungi (EPF), the interplay between these three beneficial groups is, however, unknown. Here, we present a hypothetical interaction network between aphids and their natural enemies based on three comprehensive databases compiling EPF-aphid, EPF-ground beetle, and EPF-hoverfly interactions of the European species. We aim to (1) investigate the specificity of EPF towards each group of insects, (2) assess the effect of EPF on ecosystem services provided by both carabids and hoverflies through numerical parametrization of the interaction links, and (3) investigate the role of each of the predacious agents in the dynamics of mycosis within aphid colonies. From the three separate networks linking each insect host with EPF, aphids had the highest number of EPF associations (236, 192 aphid species), then carabids (20, 12 species), and hoverflies (16, 10 species). The cross-infection network linking these three different insect hosts (214) through common EPF infection showed over 11,000 connections. Depending on EPF features, each host could potentially be a vector of EPF and can infect insects within the same guild but different taxa. How EPFs are associated with beneficial insect is less studied than that with pests, and thus we have disproportionately larger networks for aphids than for the other two taxa. Although this may hamper solid predictions of the infection pathways in real-life agricultural systems, our study helps to gain insight into the trade-off of using EPF and insect biological control agents at the same time and, ultimately, it also facilitates the adoption of suitable agricultural practices with improved biological control.
