Last revised: Sept. 5, 2001

Ischyrus quadripunctatus (Olivier)
Pleasing Fungus
Beetles
of
North America
Family Erotylidae


by Paul E. Skelley

These beetles resemble in many ways some of the tenebrionids, but they have the tarsal formula 5-5-5 (many with fourth tarsomere small); they are often marked with red, or other bright colors, and are found in association with fungus, or fungus-rotted wood.

Ecology. Larvae and adults feed on the fruiting bodies of macro Basidiomycete fungi growing in decaying wood or in mycorrhizal associations with tree roots (Goodrich & Skelley 1994, Skelley et al. 1991). A few species are known to feed on stored products permeated with mycelia (Savary 1995). Adults deposit eggs on the fungus on which the larvae feed. Larvae of the supposed primative erotylids (Megalodacne, Dacne, Microsternus) burrow in hard bracket fungi. Larvae of the higher erotylids are surface grazers on prostrate fungi or feed within mushrooms. Larvae that feed in rapidly decaying mushrooms are pale and maggot-like, with rapid development. Adults of some species (Megalodacne) overwinter under bark or beneath logs in gregarious masses. Many species show nocturnal activity (Ischyrus, Pseudischyrus), while others appear to be active during the day (Tritoma, Triplax).

Status of the classification. For North America, the family has been thoroughly revised (Boyle 1956); however, the affinities of the family are not discussed. Crowson (1955) includes this family in the vicinity of the Coccinellidae, but in his section Clavicornia. Phylogenetic studies on this family indicate a strong relationship with the Languriidae (Leschen pers. com.), which follow the more conservative relationship promoted in many catalogs and classifications.

Distribution. There are approximately 2300 described species (Alvarenga 1994, Chj & Chj 1988, 1989, 1990; Delkeskamp 1981) occurring in all areas, of which 49 occur in America north of Mexico (Boyle 1956; Goodrich & Skelley 1991, 1997; Skelley 1993, 1994, 1997)


Dacne

Microsternus

Gibbifer

Megalodacne

Ischyrus

Triplax

Hirsutotriplax

Tritoma

Pseudischyrus

Haematochiton

Mycotretus

Key to North American Genera

Bibliography

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