SEASONAL ABUNDANCE OF DIABROTICA-BALTEATA AND OTHER DIABROTICINA BEETLES (COLEOPTERA, CHRYSOMELIDAE) IN NORTHEASTERN MEXICO

Abundance and seasonality of Diabroticina species were investigated us ing black light traps in Rio Brave and San Fernando, in northern Tamau lipas, Mexico, from 1980 to 1993. Diabrotica balteata LeConte was the most abundant species with average captures of 11,666 beetles per year . Other species captured included D. undecimpunctata howardi Barber, D . longicornis (Say), D. tibialis Jacoby, Paranapiacaba connexa (LeCont e), and Acalymma trivittatum (Mannerheim). Multivoltinism was evident for D. balteata, D. undecimpunctata howardi, and A. trivittatum. Beetl es were captured more abundantly from midspring to early fall but occu rred practically year around. More than 90% of the total captures of D . balteata occurred from May through July. Flight activity of D. balte ata decreased as wind speed increased. A multiple regression model con sisting of climatic factors as independent variables (x(n)) explained 86% of the variability of total yearly catches of D. balteata (y). The model indicated abundance was adversely affected by preceding cold wi nter and early rainfall (1 January to 18 May) and was favored by rainf all from 19 May to 30 August. Periodic high captures of D. balteata du ring May to July might be caused by dispersal behavior, probably assoc iated to changes in habitat quality, i.e., corn flowering and maturati on. The results found herein are discussed in relation to those report ed for the same or related species elsewhere.