Circling back: Vespula spp. re-invasion after knockout from volcanic ash fall in Patagonia

O_LIEffective management of invasive species requires understanding re-invasion dynamics, to prevent control failures, refine methodologies, and enhance protocols. Re-invasion is the process by which eradicated or naturally disappeared exotic species establish themselves again, in previously occupied areas. Re-invasion often bypasses initial invasion phases such as transport and introduction. During re-establishment, changes in the invader, the invaded environment, and species interactions can influence the success of invasion. C_LIO_LIWe investigated re-invasion patterns of Vespula germanica and Vespula vulgaris wasps in NW Patagonia (Argentina) following a significant natural disturbance: the 2011 Puyehue-Cordon Caulle volcanic eruption, which caused unprecedented arthropod defaunation. By establishing 23 sampling sites in heavily affected regions, we conducted sampling events over three years (2012-2014). C_LIO_LIOur findings show that re-invasion of both Vespula spp. occurs fast, with minimal interspecific competition among them observed. The proximity to urban centers, acting as refuges, further facilitated their establishment. C_LIO_LIThis unique case study highlights the adaptability of these invasive wasps in the face of extreme environmental disruptions. By describing the importance of considering reinvasion routes and refuges, this research may help develop more effective management strategies to control Vespula populations. C_LI