Bolitotherus cornutus

The horned fungus beetle, also known as the forked fungus beetle, can be found in the northeastern part of United States and eastern part of Canada. (Milne and Milne, 1980)

These beetles live in dying and dead tree trunks found in forest habitats. (Evans and Bellamy, 1996; Whitlock, May, 1992)

The color of horned fungus beetles ranges from black to a dark brown. There is a distinct sexual dimorphism. While both males and females have antennae, males have two horn-shaped antennae that extend forward on the head and one forked horn on the middle of the head. Females have tubercles on the heads and a heavy plate on the back at the abdominal tip. Adults are about 8 to 12 millimeters long and have wings. They have front wings that are hardened and hind wings that are membranous. (Conner, July, 1988; Milne and Milne, 1980)

There are three stages in the development of Bolitotherus cornutus. First, the eggs are deposited in or on fungi. Next, larvae develop feeding on fungal tissues. About three months later larvae pupate, emerging as adults in late summer or in early spring after hibernating throughout the winter. (Conner, July, 1988; Milne and Milne, 1980)

During courtship a male climbs on the back of a female, twitches its body, and then it strokes the female’s head with its feet. Males with a bigger horn have a competitive advantage over other males during courtship. Though it appears that the females have no control over which male becomes interested in them, they do get to decide which male can transfer a spermatophore. The heavy plates on the female's back will open to allow the transfer of spermatophore under the voluntary power of the female only. The male then guards the female for two to five hours after courtship. (Bartalon and Brown, 1986; Conner, July, 1988)

Females copulate aproximately every nine days, and lay at least one egg per insemination. Female horned fungus beetles are very particular in selecting where they lay their eggs. The size of the larval host determines the survival of the larvae as well as the size of the horn in male offspring. (Conner, July, 1988)

Adult beetles may live up to five years. (Evans and Bellamy, 1996)

A slow-moving organism, the horned fungus beetle stays within a small area. Males become aggressive towards one another during courtship, while females lack horns and do not demonstrate any aggressive behavior. If disturbed, the beetle will feign death and remain motionless as it blends in with the rotting wood around it. Though the beetle has wings, it flies only in the rare instance of migration to another area of fungus. The beetle usually stays in the same fungus covered log from hatching til death. (Conner, July, 1988; Lundrigan, 1997; Milne and Milne, 1980; Whitlock, May, 1992)

These beetles and the larvae are saprophagous. They eat fungus off of dying or dead trees.

There are few predators of this beetle. (Conner, July, 1988)