Mycophagy in Coccinellidae: Review and synthesis

Mycophagy, though often overlooked, represents an interesting and unique ecological niche within the Coccinellidae. Facultative mycophagy has been reported from the aphidophagous Coccinellini and the polyphagous Tytthaspidini. Members of Halyziini, a cosmopolitan tribe of the Coccinellinae, are obligate mycophages specializing on the powdery mildew fungi of Erysiphales, a ubiquitous order infecting almost 10,000 angiosperm plants worldwide. Various researchers have recorded this mycophagous habit during the past 150 years, resulting in a large list of host–powdery mildew complexes around the world harboring these insects. Members of the Halyziini possess several attributes conducive to biological control, including host specificity (obligation), widespread native distribution, and strong aggregative response to host density. We compare historical attempts to quantify powdery mildew removal by Halyziini, and discuss the possible utility of mycophagous coccinellids for biological and integrated control, as well as mechanical transmission of powdery mildew inoculum through insect dispersal.