
Forked Fungus Beetle (Bolitotherus cornutus) - Courting
On Ganoderma curtisii (Golden Reishi) by an old rotted Willow Oak in a backyard habitat.
Bolitotherus cornutus is darkling beetle which feeds on species of Ganoderma (Reishi) fungi. This species exhibits sexual dimorphism; males have a pair of prominent forward-facing horns on the thorax. Note the tiny cephalic horns (on the head)!
B. cornutus has an interesting mating ritual which is performed upon the host fungus. The male grips the elytra of the female, placing his thorax over the end of her abdomen. This puts him in an opposing position to the female (seen in the photos). This courting behavior lasts for several hours and is followed by the reversal of positions and the alignment of abdomens for successful copulation. This act must be fully consensual as the female has thick plates on her back which must be voluntarily opened to allow for the transfer of the spermatophore.
Side note: The hairy thoracic horns are used in pushing around other males whilst competing for mates and territories.

''Bolitotherus cornutus'' is a North American species of darkling beetle known as the forked fungus beetle. As a holometabolic insect, its life cycle includes four life stages: egg, larva, pupa, and adult. All life stages are associated with the fruiting bodies of a wood-decaying shelf fungus, commonly ''Ganoderma applanatum'', ''Ganoderma tsugae'', and ''Ganoderma lucidum''.

comments (8)
The female has thick plates on her back which must be voluntarily opened to allow for the transfer of the spermatophore! Posted 7 years ago
OH, and I added an extra note about the "hairy" horns in the description! I couldn't resist! Posted 7 years ago