Cyrtarachninae
Guides
Mastophora
bolas spiders, American bolas spiders
Mastophora is a genus of orb-weaver spiders in the family Araneidae, commonly known as bolas spiders. These spiders have abandoned the typical orb-web construction of their relatives and instead hunt using a unique method: they produce a single droplet of sticky silk suspended on a thread (the "bolas") and swing it to capture flying prey. Adult females are nocturnal moth specialists that use aggressive chemical mimicry, releasing sex pheromones to attract specific male moth species within range of their bolas. The genus includes 15 species in the United States, with Mastophora cornigera being the only species found in California.