Type species

Monarthrum chapuisi Kirsch

Adapted from Wood 1982, p. 1206-1245


Monarthrum can be easily distinguished in this complex group by the 2-segmented funicle and by the usually margined apical tip of the elytra.


Species in this genus range from 1.4 to 4.8 mm in length and are approximately 2.4 to 3.4 times as long as wide. Their color ranges from yellowish brown to very dark brown with many species being bicolored. The pronotum is longer than wide, asperate anteriorly, and with the anterior margin serrate in males. The scutellum is large and flushed with the elytral surface. The declivity is convex to concave, unarmed or armed by spines, and its apex varies from entire to emarginate. The metepisternum is only visible anteriorly. The vestiture is rarely present, if so, it is only at the declivity. Some females have their frons elaborately ornamented by hair-like setae. The anterior margin of the compound eye is emarginate. The scape is longer than the 2-segmented funicle, and it is either slender or triangular, bearing long hairs in females of some species. The club is relatively large and variable in shape with two straight to procurved sutures usually present; its posterior face is usually ornamented by long hair in females. The procoxae are contiguous.


United States to Argentina

World fauna

Number of species: 131, Native species: 5, Introduced species: 0


Acer, Alexia, Alnus, Betuia, Brunellia, Carya, Castanea, Chrysolepsis, Clusia, Coffea, Erythrina, Fagus, Ficus, Inga, Liquidambar, Lithocarpus, Mimosa, Nectandra, Nyassa, Ochroma, Parkinsonia, Pinus, Podocarpus, Prunus, Spondias, Quercus, Tilia, Theobroma