Meeting Abstract
Mason spiders are a member of the sac spider family, Corinnidae. Unlike other Corinnids, mason spiders cover their egg sacs with pebble mounds. I discovered mason spiders in the Snake River Canyon of Wyoming where in July and August, female mason spiders lay eggs on the exposed surfaces of rocks. They then cover each egg sac with mounds of pebbles, sealing each pebble in place with silk. Using observational and experimental field data from the summers of 2014 and 2015, I have described the natural history and behavior of this newly discovered species and its unusual behavior. I have determined that while some female mason spiders build mounds of varying sizes, other females do not. My findings also suggest that mason spider mounds protect egg sacs from predation by a parasitoid wasp (Gelis).
