Forked Fungus Beetle (suggested common name) Bolitotherus cornutus (Panzer) 1794 (Insecta: Coleoptera: Tenebrionidae)

The forked fungus beetle, Bolitotherus cornutus (Panzer), is a cryptic horned beetle in the family Tenebrionidae that is found throughout much of eastern North America. The most distinctive feature of the forked fungus beetle is a pair of forward-facing horns that emerge from the thorax of the adult male (Figure 1). Males use these horns in competitions with rivals for access to reproductive opportunities with females. These beetles spend most of their lives on or within shelf fungi that grow on decaying logs. The fascinating life history of the forked fungus beetle makes this insect an excellent model for studying behavior, population dynamics, and sexual selection.

Effect of spatial scale on habitat use of Bolitotherus cornutus (Coleoptera: Tenebrionidae)

The habitat of Bolitotherus cornutus Panzer consists primarily of sporophores of the shelf fungus Fomes fomentarius (L.:Fr.) J. Kickx fil. Each sporophore is discrete and often several are present on a single dead log or standing snag, especially of paper birch (Betula papyrifera Marsh.). An exploratory approach was used to examine habitat use at three scales (the single sporophore, a single log supporting up to several sporophores, and a group of logs supporting sporophores) by modeling incidence of adult B. cornutus. Sporophore volume and decay were important for the beetles at all scales. Patches containing a variety of states of sporophores from alive to dead and decomposing are probably most suitable to B. cornutus. Results are compared with those for the related European beetle Bolitophagus reticulatus (L.), which is similar ecologically and also occupies F. fomentarius sporophores.