Do the giant pill-millipedes (Arthrosphaera: Sphaerotheriida) disseminate arbuscular mycorrhizal spores in the Western Ghats?

Giant pill-millipedes constitute one of the conspicuous soil macrofauna involved in degradation of plant detritus in forests of the Western Ghats of India. Faecal pellets of two pill-millipedes (Arthrosphaera disticta and A. fumosa) and soil from their habitats was examined for viable spores of arbuscular mycorrhizal (AM) fungi. The faecal pellets of the two millipedes contained 16 species (14 species in common) of AM fungi whereas there were 19 species in soil. Up to 218 spores/100 g dry mass of faecal pellets were recorded and 97 % of the AM spores were viable. There was up to 332 spores/100 g dry in the soil and the diversity of AM fungi was higher in soil than in faecal pellets. Of the five most common species in soil, three (Glomus hoi, G. mossae and Glomus sp. 2) were also frequent in the faecal pellets of both millipedes. It is hypothesized that a mutual relationship between plant species, AM fungi and the pill-millipedes could have been established in the Devonian period and this is briefly discussed.