Population dynamics of Western corn rootworm beetles on different varieties of maize identified using pheromone and floral baited traps

Abstract

The present paper presents details of the population dynamics of Diabrotica v. virgifera LeConte beetles on six maize varieties of three different maturity classes, i.e. early (FAO 190), medium-early (FAO 250) and mediumlate (FAO 280-300), grown in Central and Eastern Europe. The study was conducted in 2009/10 in the southeastern part of Poland. The D. virgifera beetles were captured using two types of trap: pheromone (PTs) and floral-baited (FTs). Significant differences in beetle counts were found between: (i) the first and second year of the study (higher in 2009 than in 2010); (ii) the varieties of maize and their different growth stages; (iii) early and medium-late varieties of maize. Initially, depending on the availability of maize silk and pollen, the most numerous D. virgifera beetles were found on the early varieties followed by the medium-late varieties. The study also revealed a significant difference in the performance of the two types of trap used to monitor the number of adults, particularly during the initial period when arrival rates were high. Pheromone traps were more effective in catching D. virgifera beetles, especially during the flowering stage of maize. Floral-baited traps were most effective at the end of the active growth of maize, when the preferred food of D. virgifera was unavailable.