Abstract

The study of the impact of thermal variability on the performance of individuals is important to understand the microhabitat selection and the responses of organisms to different climate scenarios. In this study we explore the performance of the Chilean recluse spider, Loxosceles laeta, of great medical importance, measuring the activity of spiders under different temperatures in a range of usual environmental temperatures in Chile. Optimum temperature for a speed performance agree with preferred temperatures previously reported in the evening and night, in which spider bites on human usually occur. Also, the maximum estimated temperature for movement (CTmax) agrees with temperatures reported to suppress coordinated activity, but the minimum estimated temperature for movement (CTmin) is lower than in other araneomorph spiders and higher than previous reported minimum temperatures that suppress coordinated movements and lethal temperatures. High CTmax and low CTmin could be explained by adaptation of this species to arid environments with Mediterranean climate. The performance curve suggest that L. laeta is adapted to high temperatures in the range of usual indoor temperatures of human dwellings.