Behavioral observation of two fungivorous beetles (Coleoptera: Tenebrionidae) on wood-decaying bracket fungus Cryptoporus volvatus

摘要

The behavior of two sympatric beetles, Parabolitophagus felix Lewis and Ischnodactylus loripes Lewis (Tenebrionidae: Coleoptera), specialists of a bracket fungus Cryptoporus volvatus (Peck) Shear, was studied in Kyoto, central Japan. A sporocarp of C. volvatus has a distinct white volva, and a small elliptical ostiole near the base. Adults of two tenebrionids use the volval chambers of a sporocarp as mating space. Adults walked across closely located sporocarps infrequently on a tree at night (19.30-20.30 h). Field observation showed that the occupancy patterns of the volval chambers in the two species were temporally segregated: Parabolitophagus felix occupied them until May, while I. loripes occupied them in late May to early June