Seasonal and Vertical Distribution of Dalbulus maidis (Hemiptera: Cicadellidae) in Brazilian Corn Fields

Abstract

The corn leafhopper, Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae), is one of the most important pests of corn, Zea mays L. (Poaceae), in Latin America. We assessed the seasonal and vertical distribution of D. maidis in corn fields in Brazil, in addition to describing the effect of 2 types of yellow traps positioned at 2 heights on the capture of this leafhopper. Sampling was conducted using yellow pan traps and yellow sticky cards throughout the cropping period, in both the rainy and dry seasons. The population of D. maidis in the dry season was much larger than in the rainy season. During both the rainy season and dry seasons, the greatest abundance of D. maidis was observed at 77 d post emergence of the corn, which corresponded to physiological maturity. Greater numbers of insects were captured with yellow cards than with pan traps, at both heights and in both cropping seasons. Also, more insects were captured at the 1.5 m than at the 0.5 m sampling height. The corn leafhopper was able to maintain significant populations throughout the phenological cycle of corn, but was especially numerous in the dry season. Knowledge of the seasonality of D. maidis aids in understanding how population dynamics may change with cropping seasons.