In samplings carried out in Tucumán (Argentina) Maecolaspis monrosi Bechyné was observed for the first time damaging soybean. This species is a chrysomelid Eumolpinae which belonged to Maecolaspis lebasi group. Species of this group are very hard to recognize because all of them possess similar coloration and elytral punctate. The objective of this paper is the identification of M. monrosi adding new diagnostic characters: mouth parts, alar venation and male and female genitalia. The male of M. monrosi is described for the first time and new host plants are recorded.
Insecta; morphology
