Invasive brown widow spiders disperse aerially under a broad range of environmental conditions

Spiders commonly disperse on silk lines as juveniles by means of rappelling or ballooning. These modes dispersal, especially long-distance dispersal via ballooning, can greatly increase the distance an individual move and, at population level, speed range expansion and likelihood gene flow. Nevertheless, few studies have examined how spiders under field conditions, which environmental meteorological conditions may affect their decision to disperse. We tested spiderlings invasive brown widow (Latrodectus geometricus) in Negev Desert Israel. documented pre-dispersal (climbing tiptoeing) (short-distance ballooning) behaviours during day (n = 147 spiders) night 171 spiders), while recording wind speed, temperature humidity. found that ballooned significantly more (14.3%) compared with 1.8% ballooning night. At night, were likely higher speeds, lower humidity, whereas day, factors less predictive behaviour. In addition, we significant differences proportion showing behaviour depending family line. conjunction human-mediated be important mechanism spider. Understanding genetic affecting lead better management species.