Tools for monitoring oak defoliating geometrids – traps for catching males and females

Abstract

ABSTRACT Several insect species, including those belonging to Geometridae, pose serious threats to oak stands, primarily by causing cyclic defoliation and increasing the vulnerability of trees to adverse secondary factors. Our major study goal was to compare the effectiveness of two types of pheromone traps, funnel vs. bucket traps, for capturing Operophtera brumata males, and the effectiveness of two types of barrier traps, glue bands vs. collar traps, installed on tree trunks for capturing flightless geometrid females that climb host trees to mate and oviposit. The relationship between catches of O. brumata males and females captured using the funnel and collar traps, respectively, was also assessed. The numbers of males in the two types of pheromone traps did not differ significantly, and the practical use of these traps is discussed. Among the traps targeting females, the collar traps showed much higher effectiveness than the glue bands. The relationship between the O. brumata male and female catches was significant and was described by an exponential function, which can be used for estimating female density using male catches and vice versa. Our study found significant advantages of collar traps over glue bands for monitoring oak defoliating geometrid species.