Monotoma americana

Monotoma Herbst 1793


Monotoma is in the monogeneric tribe Monotomini Laporte 1840, within the subfamily Monotominae Laporte 1840. Affinities to other monotomid genera are not well understood. There are three subgenera: Monotoma for the majority of species, Monotomina for two European species (one of which has been introduced in numerous localities around the world, including North America), and Gyrocecis for three species known to be associated with ants in the Formica rufa species group (Bousquet & Laplante 1999). The only New World species of the latter subgenus is Monotoma myrmecophila. The type species is the now cosmopolitan Monotoma picipes.


Monotoma can be easily distinguished from other New World genera by the coarse subcontiguous punctures on the head dorsally and on the pronotum (except in Monotoma longicollis), and by the protruding anterior angles of the pronotum. Most are covered in moderately dense setae, which can become almost scale-like in some species.


Although most Monotoma species are considered to be "mold" feeders, little is known about the biology of this genus. Gut dissections of Monotoma producta have found spores of Fungi Imperfecti, and Monotoma spp. are often found in mold-associated habitats, including man-made ones such as compost heaps and haystacks. Some species, such as Monotoma longicollis, have been associated with stored food products, and are often attracted to fermenting (or fermented) products such as beer (TCM, pers. obs.). The subgenus Gyrocecis is associated with Formica rufa-group ants, usually found within their refuse piles. Monotoma hoffmani, found in Mexico and probably surrounding areas, is also known to be associated with Atta ants (Hinton & Ancona 1935). Monotoma producta can be found in large numbers in decaying piles of beach wrack along the Atlantic coast of North America (Bousquet & Laplante 1999)


Species are known to be native to Europe, Asia, India, North Africa, Madagascar, North America, and Central America. Several (e.g. M. johnsoni, M. longicollis, M. picipes, and M. spinicollis), have been introduced around the world. The genus has become cosmopolitan, expanding its range to include Australia and New Zealand (where native species are not known).

List of New World Species


Aubé 1837
Casey 1916
Villa & Villa 1835
Bousquet & Laplante 1999
Hinton & Ancona 1935
Bousquet & Laplante 1999
(Gyllenhal 1827)
Bousquet & Laplante 1999
Herbst 1793
LeConte 1855
Aubé 1837
Aubé 1837
Motschulsky 1845

Not photographed:

Suggested References

Bousquet & Laplante 1999 - review of Canadian (and most North American) species

Local faunal treatments: Hirano (2009) [Japan], Kuschel (1979) [New Zealand], Johnson & Otero (2010) [Monotomina; Iberian Peninsula], Majka & Bousquet (2010) [Maritime Canada], Mifsud & Jelinek (2012) [Maltese Islands], Nikitsky (1986) [Russia & Soviet Far East], Otero (1991) [Gyrocecis & Monotomina; Iberian Peninsula], Otero & Diaz-Pazos (1994) [Monotoma s.s.; Iberian Peninsula], and Peacock (1977) [Great Britain]