Medically Significant Spiders in Missouri
Brown Recluse
The brown recluse spiders body size varies from ⅓” to ½” in size with the overall size including legs can be 1” or greater. The body is yellow to dark brown with a darker brown violin-shaped mark on the top of the cephalothorax right behind the eyes. Usually found indoors, particularly bathrooms, bedrooms, closets, garages, basements, attics and cellars.
Black Widow
The black widow abdomen size can range from ¼” to ½” in diameter with the males being much smaller. The abdomens are shiny black with two reddish or yellowish triangles or spots on the abdomen (depending on the black widow subspecies). Usually found underneath things like boards, landscaping stones/blocks, along foundations, behind shrubs, and especially where brick or wood extends close to the ground.
Other Common Spiders in Missouri
Wolf Spiders
The Wolf spider is a relatively large spider. They can range in sizes from 1/4” to 2” long. They are nocturnal ground hunters, so they do not spin a web to catch their prey rather they hunt for it and run it down if need be. Their diet consists of insects like flies, ants, grasshoppers and crickets. Typically they stay outdoors unless seeking shelter from the cold weather and typically found in garage, basements, crawlspaces and storage areas.
Cellar Spider
Cellar spiders are both long-bodied and short-bodied spiders that are normally found in dark and damp places like basements, crawlspaces, garages and cellars. Typically the adult female long-bodied cellar spider are about 1/4″ to 5/16″ with the front legs about 1 3/4″ to 1 15/16″ long. Males bodies are around 1/4″ long.
Yellow Garden Spider
Yellow garden spiders are found throughout the US and are most commonly found in gardens, fields and clearings. Being a part of the orb weaver family, they spin circular webs strung from twigs, leaves, branches, a/c units and homes in sunny areas. In females, the top side of the abdomen is black with symmetrical patches of bright yellow. The legs are reddish brown at the base and black towards the tips. Typically the average size of a female is 3/4″ to 1 1/8″ with the males being three times smaller. Males have brownish legs and less yellow coloration on their abdomens.
Furrow Orb Weaver
Furrow Orb Weavers bodies are usually about 1/2″ long with the males being slightly smaller. They have tan, brown, grayish, reddish or olive colored abdomen with a dark zigzag pattern down the length of the abdomen. These orb weavers mainly build their webs outdoors in moist areas, as well as, eves of homes, a/c units, decks, hand railings and other such things. Their diet consists mainly of gnats, mosquitos and damselflies.
