Abundance and seasonality of Diabroticina species were investigated using black light traps in Rio Bravo and San Fernando, in northern Tamaulipas, Mexico, from 1980 to 1993.Diabrotica balteataLeConte was the most abundant species with average captures of 11,666 beetles per year. Other species captured includedD. undecimpunctata howardi Barber,D. longicomis(Say),D. tibialisJacoby,Paranapiacaba connexa(LeConte), andAcalymma trivittatum(Mannerheim). Multivoltinism was evident forD. balteata,D. undecimpunctata howardi, andA. trivittatum. Beetles were captured more abundantly from midspring to early fall but occurred practically year around. More than 90% of the total captures ofD. balteataoccurred from May through July. Flight activity ofD. balteatadecreased as wind speed increased. A multiple regression model consisting of climatic factors as independent variables (xn) explained 86% of the variability of total yearly catches ofD. balteata(y). The model indicated abundance was adversely affected by preceding cold winter and early rainfall (1 January to 18 May) and was favored by rainfall from 19 May to 30 August. Periodic high captures ofD. balteataduring May to July might be caused by dispersal behavior, probably associated to changes in habitat quality, i.e., corn flowering and maturation. The results found herein are discussed in relation to those reported for the same or related species elsewhere.