Distribution, dispersal and spread of the invasive social wasp (Vespula germanica) in Argentina

Abstract

Se estudió la distribución y difusión de la avispa invasora sociales Vespula germanica en Argentina, se centra en la contribución de la dispersión de la reina de la expansión territorial. Vespula germanica es originaria de Eurasia y ha invadido varias regiones del mundo, incluyendo el sur de Argentina. potencial de vuelo de reinas recogidas en el campo se midió usando molinos de vuelo. Además, por medio de una amplia encuesta se estimó la tasa de propagación mediante el análisis la relación entre los años transcurridos desde la llegada y la distancia desde la localidad introducción

We studied the distribution and spread of the invasive social wasp Vespula germanica in Argentina, focusing on the contribution of queen dispersal to territorial expansion. Vespula germanica is native to Eurasia and has invaded several regions of the world, including Southern Argentina. Flight potential of field-collected queens was measured using flight mills. Also, by means of an extensive survey we estimated the rate of spread by analysing the relationship between years since arrival and distance from the introduction locality. The mean distance flown by wasp queens in flight mills was 404.7 ± 140.8 m (mean ± SE, n = 59), while the rate of spread of V. germanica was estimated at 37.2 ± 2.1 km year−1 (mean ± SE, n = 67), although faster towards the south. The observed spread rate of V. germanica wasps in Argentina confirms the invasive potential shown by several Hymenoptera species worldwide. Still, a stratified geographical expansion pattern does not match observed queen dispersal abilities, suggesting that human-aided transport of hibernating queens is the central driver of the current distribution of these wasps. We suggest that despite several life-history traits known for social insects that contribute to successful invasion, wasp spread must still rely strongly on human mediated pathways. This observation sheds light on those factors that are crucial for managing invasions of this and related pestiferous wasps