Crab spiders prefer your garden, grassy areas and urban parks rather than indoor environments, with the exception of greenhouses. In greenhouses and gardens, crab spiders can be problematic to workers who may experience the discomfort of itchy, stinging bites. Because spider crabs can blend in with their environments, they may not be easy to spot on flowers and foliage. In greenhouses in Hawaii, workers have reported feeling the silk of a spider crab and then finding itchy bites on their arms and necks. As crab spiders do not spin webs, there is no sign that a spider is nearby.
As to infestations, spiders, unlike some of the more social pests, such as ants, bees and wasps do not build colonies or nests. Lone hunters, crab spiders patiently wait for their prey to cross their path before jumping out and paralyzing their prey with their neuro-toxic venom in order to feast on their prey. Because pollinators are on the crab spider’s menu, they can reduce pollination in areas where honeybees and wasps steer clear of certain flowers and plants that they know crab spiders may be lurking near. On the other hand, crab spiders help to prevent mosquito and fly infestations in your backyard.