Moth-predator
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.
Mastophora hutchinsoni
American bolas spider, Cornfield Bolas Spider
Mastophora hutchinsoni is a bolas spider in the orb-weaver family Araneidae, notable for its highly specialized hunting strategy that abandons the typical orb web in favor of a single adhesive droplet on a silk thread. Adult females use aggressive chemical mimicry to attract male moths by releasing species-specific sex pheromone blends, then capture prey by swinging this 'bolas' at hovering moths. The species exhibits extreme sexual dimorphism, with females developing into large, globular spiders while males remain small and retain juvenile hunting behaviors. It occurs throughout eastern North America and has been extensively studied in Kentucky populations.