El efecto del trampeo masivo de avispas de Vespula germanica sobre la abundancia y la actividad de nidos de dicha en especie en parcelas ubicadas en San Carlos de Bariloche, Río Negro, Patagonia Argentina

Abstract

Vespula germanica is a social wasp that has invaded many parts of the world becoming a pest, mainly in urban environments. Despite extensive research on ecology and control, there are currently no effective, sustainable strategies to manage populations in the invaded range. We evaluated the effects of worker mass trapping on V. germanica abundance and nest activity in Southern Argentina, where these wasps are widespread since the early 1980’s. During two consecutive years, a mass trapping protocol assay was deployed in four plots of one hectare each. Mass trapping consisted of placing 25 non-toxic meat-baited traps, 20 meters apart from each other, creating a grid of 5x5 traps during 4 weeks. Wasp abundance and the traffic rate of all the nests present in the plots were measured one week before and one after mass trapping. Our results showed that mass trapping of workers resulted in a 65% reduction in local wasp abundance and a 48% in traffic of nests withing the treated area. Similarly, a decrease in wasp abundance was obtained one year after mass trapping. Mass trapping of workers may prove to be a useful, and environmentally friendly tool to decrease invasive social wasp abundance locally and during peak activity.