Corley, J. C. | bioRxiv Science

bioRxiv2024

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

ecology↗

bioRxiv2023

Chemotactile perception and associative learning of amino acids in yellowjacket workers

Learning and memory are essential for animal survival, influencing preferences, decision-making, and foraging behaviour. In this study, we explore the perceptual and learning abilities of Vespula germanica (yellowjacket wasps) to various amino acids. We hypothesize that V. germanica can qualitatively evaluate various amino acid solutions, given their scavenging habits and the possibility of metabolizing amino acids to fuel energy. Through chemo-tactile differential conditioning, we studied worker wasp maxilla labium extension response (MaLER) to essential (Lysine, Tryptophan, Arginine) and non-essential amino acids (Ornithine, Aspartic acid, Glycine). Conditioning sessions included individual amino acids against water and comparisons between different amino acids. Additionally, we tested retention, discrimination, and generalization abilities, 30 minutes later with conditioned and novel stimuli. Our results show that wasps exhibit the ability to learn and discriminate various amino acids. The discrimination capacity extended to differentiating between pairs of amino acids. Memory retention was generally robust, but certain associations observed during conditioning did not persist after a 30-minute interval. Moreover, when wasps were trained with essential amino acids, the acquired learning did not generally extend to other non-essential amino acids, except for Arginine, which exhibited generalization when tested with its precursor, Ornithine. Conversely, when trained with non-essential amino acids, the acquired learning generalized to other essential amino acids. These results suggest that, unlike other hymenopterans, wasps can detect, discriminate, and generalize free amino acids, crucial for their foraging decisions. This knowledge contributes to understanding the cognitive dimensions of V. germanica and their implications for targeted pest management. Summary statementThis study on Vespula germanicas amino acid perception enhances our understanding of foraging behaviours. The findings contribute to insect cognition studies, with potential implications for pest management.

animal behavior and cognition↗