Seasonal Abundance of Diabrotica balteata and Other Diabroticina Beetles (Coleoptera: Chrysomelidae) in Northeastern Mexico

Abstract

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 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. longicomis (Say), D. tibialis Jacoby, Paranapiacaba connexa (LeConte), and Acalymma trivittatum (Mannerheim). Multivoltinism was evident for D. balteata , D. undecimpunctata howardi , and A. trivittatum . Beetles were captured more abundantly from midspring to early fall but occurred practically year around. More than 90% of the total captures of D. balteata occurred from May through July. Flight activity of D. balteata decreased as wind speed increased. A multiple regression model consisting 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 winter and early rainfall (1 January to 18 May) and was favored by rainfall from 19 May to 30 August. Periodic high captures of D. balteata during 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.