Akanthomyces aranearum (All Fungi)
Anamorph: host covered by white, cream to grey-yellow mycelium from which numerous synnemata arise. Synnemata arising from all parts of the host, clavate to cylindrical, 0.8-1.8 mm long, slender, 62-74 µm diam below, simple or occasionally branched, dark brown at the base, becoming yellowish white to orange-white towards the upper fertile portion, composed of parallel hyphae. Hyphae of synnema smooth, hyaline to dark orange, sometimes swollen, 3- 6 µm diam. Conidiogenous cells proliferating percurrently (phialidic), forming a dense layer on the synnema surface, consisting of a globose to ellipsoidal cell 5-12 x 4-6.5 µm in size, asperulate to verrucose, abruptly narrowing into a short, smooth neck, 0.8-2.0 µm long and 0.8-1.5 µm diam. Conidia 4.5-11.5 x 2-2.5 µm, narrowly obclavate, often acute at the lower end, narrowing upward, rounded or obtuse at the upper end, one-celled, hyaline, smooth, forming short fragile chains.
Teleomorph: an association with Cordyceps thaxteri was observed by Mains (1950), but the link has not been confirmed using cultural or molecular methods.
No molecular data are available for this species. As currently circumscribed, it has an extremely wide distribution in both temperate and tropical biomes, and may represent a species aggregate.
Associated with a wide range of spiders, and apparently a pathogen.
In GB&I, scattered throughout the southern half of Great Britain, including records from Devon, Cheshire, Hampshire and Warwickshire. Also recorded from tropical west Africa, North America and S and SE Asia.