Spider-pathogenic fungi within Hypocreales (Ascomycota): their current nomenclature, diversity, and distribution

Spider-pathogenic fungi are widely distributed in the world. Our review shows at least eighty six spider- and harvestman-pathogenic fungi that are currently accommodated in genera Akanthomyces Lebert, Beauveria Vuill., Clonostachys Corda, Cordyceps Fr., Engyodontium de Hoog, Gibellula Cavara, Hevansia Luangsa-ard et al., Hirsutella Pat., Hymenostilbe Petch, Lecanicillium W. Gams & Zare, Ophiocordyceps Petch, Purpureocillium Luangsa-ard et al., and Torrubiella Boud. within Hypocreales. Akanthomyces neoaraneogenum (W.H. Chen, Y.F. Han, J.D. Liang, Z.Q. Liang & D.C. Jin) W.H. Chen, Y.F. Han & Z.Q. Liang, comb. nov. is also proposed here. Among the genera, Gibellula, Hevansia, Torrubiella, and Akanthomyces are exclusively or dominantly spider pathogens. Gibellula pulchra, G. leiopus, P. atypicola, A. aranearum, and T. aranicida are some of the cosmopolitan spider-pathogenic fungi. A total of twenty spider families and two harvestman families are known to be parasitized by hypocrealean fungi. Spider-pathogenic fungi are known from diverse areas of Europe, and Central and South America, but are only known from limited parts in Asia and Africa. However, east and southeast Asia shows the highest richness of spider-pathogenic fungi. Among three entomogenous families within Hypocreales, we show that the majority of the spider pathogens are distributed in Cordycipitaceae while a few in Ophiocordycipitaceae, but none in the family Clavicipitaceae. Through this review, we show that spiders constitute one of the major host groups of arthropod-associated fungi and hope a continuous interest will be generated to utilize such fungal resources through in vitro growth and extraction of useful bio-active secondary metabolites (extrolites).