(2) Places to find entomopathogenic fungi

 

Fruiting bodies of insect-borne fungi form after the death of insects. Accordingly, they appear in habitats that support suitably dense populations of the host insects. In general, most Cordyceps species form their stromata on affected insects in the soil, and the upper, fertile portions of the stromata emerge above ground to allow spore dispersal.

The insects affected by fungi that behave in such a manner are most often cicadas or beetles (especially those in the families Scarabaeidae, Elateridae, and Carabidae). Less commonly, the buried cadavers from which Cordyceps stromata arise are found to be hymenopterans (particularly ants and wasps), moth larvae, or beetles from other families. The main taxa producing the subterranean/aerial stromata are Cordyceps militaris, C. kyushuensis, Ophiocordyceps agriotis and C. pruinosa. Those Cordyceps species that form stromata either under layers of fallen leaves include Ophiocordyceps . nutans, Ophiocordyceps  sphecocephala, Ophiocordyceps tricentri, C. scarabaeicola, and the conidial species Akanthomyces aculeatus and Paecilomyces japonica. Cordyceps arising out of hosts in decaying wood usually have carabid bettles or moth larvae as hosts. Other pathogens occur in much more exposed positions on twigs or directly on top of rotting wood and are easily differentiated from the substrate on which they are found; these usually include hosts such as dragonflies (with fungi such as Ophiocordyceps agriotis, C. martialis, Hymenostilbe odonatae, Paecilomyces japonica and Torrubiella species. Other fungal entomopathogens that also tend to be found in exposed positions on various surfaces may occur either on the ground, on wood, on fallen or living leaves, mosses, or other substrates and affect hosts such as spiders, pupae or lepidopterans or other insects, and ants. Torrubiella species affect primarily spiders and are usually found on the undersides of leaves. Hymenostilbe odonatae attacks dragonflies and is usually found in exposed positions on twigs or branches or, less often, directly on the ground.