Spiders in Missouri

What spiders live in Missouri?

Missouri packs an unusual amount of habitat into one state: glaciated prairie in the north, the forested Ozark highlands and their dry limestone glades in the south, the Bootheel's flat delta soils, two major river systems and more than seven thousand caves. That variety, combined with hot summers and moderate winters, produces a rich spider fauna running to several hundred documented species. The eighteen profiled below are the ones Missourians actually encounter.

Orb weavers dominate the late-summer landscape. The arrowhead orb weaver is unmistakable — a white triangular abdomen, and the spider sits head-up in the centre of its web instead of hanging head-down like everything else. The spined micrathena strings small, tough webs at face height across woodland trails, and banded garden spiders, furrow and Hentz orb weavers and the marbled orb weaver fill hedgerows and porch lights.

The hunters are just as varied. The bold jumper is the salticid most often photographed on a fence rail, the flame-orange Apache jumping spider belongs to sunbaked glades and prairie, and the ground is worked at night by Tigrosa georgicola and the rabid wolf spider.

Which Missouri spiders are dangerous?

Missouri lies in the core of the brown recluse range, and population densities here are among the highest anywhere. An older house can hold hundreds of recluses for years without a single bite, because the spider retreats rather than confronts. Identify it by six eyes in three pairs instead of eight, uniformly tan legs with no bands and no heavy spines, a plain abdomen, and the darker violin mark whose neck points backwards. Most bites settle into a sore red patch and heal; a minority form a slowly enlarging ulcer that takes weeks to close. Serious systemic illness is uncommon and deaths are exceedingly rare.

Missouri also has two widows, not one. The northern black widow holds the wooded northern and eastern counties, its hourglass split into two separate red bars with a row of red spots along the back, while the southern black widow, with a complete hourglass, is the widow of the southern half of the state. Both hang upside down in strong, untidy webs near ground level in woodpiles, meter boxes, crawl spaces, barns and glade rock. Widow venom is neurotoxic, bringing cramping pain, sweating and abdominal rigidity within hours; it responds well to treatment.

What the older Missouri list gets wrong

Missouri does have a tarantula. The Texas brown tarantula reaches its north-eastern limit on the dry limestone and dolomite glades of southern Missouri, where males famously wander in daylight during the autumn mating season. It is the largest spider in the state, it is placid, and its bite is not medically significant. It does not occur in central or northern Missouri.

Wolf spiders are not the state's largest spiders. They are heavy and fast, but the tarantula outweighs them in the south and the dark fishing spider beats them on leg span statewide.

The rabid wolf spider has nothing to do with rabies. The name comes from its frantic running. It is a common, harmless ground hunter of fields and gardens that ends up indoors in autumn.

Only the northern widow is listed on the old chart. The southern black widow is at least as common in southern Missouri, and telling the two apart matters less than recognising the shape of the web and the red marking underneath.

Where you meet them

Rivers, springs and Ozark streams

Three Dolomedes species live here. The six-spotted fishing spider skates the still edges of ponds and spring branches, the whitebanded fishing spider flattens itself against streamside tree trunks, and the dark fishing spider strays far from water onto porches, barns and house walls.

Glades, bluffs and caves

Missouri's glades are miniature deserts on limestone, warm enough for the tarantula, the Apache jumping spider and both widows. Cave entrances and bluff shelters hold shade-adapted sheet-web builders, and the deep karst supports specialised cave species found nowhere else.

House, barn and basement

Recluses take dry, undisturbed interior spaces such as cardboard boxes, closets and attics; the long-bodied cellar spider owns basement ceilings; and wolf spiders come in at ground level through gaps under doors.

Spider season in Missouri

August to October is the visible season. Spiders hatched in spring reach adult size, orb webs appear across doorways overnight — the nightly rebuilding cycle is covered in our guide to the spider web — and mature males leave cover to search for females. That autumn wandering is also when male tarantulas cross Ozark roads in numbers and when wolf spiders start appearing in Missouri basements.

Winter shuts down the outdoor fauna. Most species overwinter as eggs in silk sacs or as part-grown juveniles under bark, rock and leaf litter, and a warm February week will bring wolf and jumping spiders out onto sunlit walls. Recluse populations inside heated buildings never stop, which is why bites in Missouri are reported in every month of the year.

Easy mix-ups in Missouri

In a state this full of recluses, every tan spider gets accused, and the accusation is often wrong. The checks that work are six eyes in three pairs rather than eight, evenly tan legs without bands or heavy spines, and a plain abdomen. The violin mark alone proves little, because male funnel weavers, the broad-faced sac spider and several wolf spiders carry a similar dark patch.

Glossy Steatoda cobweb spiders are called widows every autumn and never show red beneath. Bites blamed on yellow sac spiders do not cause necrotic wounds — that claim has not survived clinical study. There is no hobo spider in Missouri; the funnel webs in lawns and garages belong to harmless grass spiders. Harvestmen, with one fused body section and no venom glands, are not spiders at all.

Common Spiders in Missouri

• Triangulate Orb-weaver (Verrucosa arenata)
• Yellow Garden (Argiope aurantia)
• Banded Garden (Argiope trifasciata)
• Goldenrod Crab (Misumena vatia)
• Members of the Wolf (Lycosidae) family

Largest Spiders in Missouri

• Species of the Wolf (Lycosidae) family

Highly Venomous Spiders in Missouri

Cobweb (Theridiidae)

Cobweb SpidersNorthern Black Widow (Latrodectus variolus)Identify the northern black widow (Latrodectus variolus): the split hourglass, red dorsal spots, where it lives, and what a bite really does

Sicariidae

Sicariidae SpidersBrown Recluse Spider (Loxosceles reclusa)How to identify a brown recluse (Loxosceles reclusa): six eyes, violin mark, where it lives, and what a recluse bite really does to skin.

Less Venomous Spiders in Missouri

Orb-Weaver (Araneidae)

Orb WeaversFurrow (Larinioides cornutus)Identify the furrow spider (Larinioides cornutus): the foliate abdomen mark, its nightly orb web beside water, range, diet and whether the bOrb WeaversMarbled Orb-weaver (Araneus marmoreus)Identify the marbled orb weaver (Araneus marmoreus): marbled abdomen, the orange pumpkin spider form, size, web and retreat, range, and whetLong-Jawed SpidersOrchard Orbweaver (Leucauge venusta)Identify the orchard orbweaver (Leucauge venusta): size, silver and green colours, its horizontal orb web, where it lives and whether the biOrb WeaversSpotted Orb Weaver (Neoscona crucifera)Identify the spotted orb weaver (Neoscona crucifera): rusty hairy body, ringed legs, size, the web it rebuilds nightly, range and whether itOrb WeaversBanded Garden (Argiope trifasciata)Identify the banded garden spider (Argiope trifasciata): silver banding, size, the zigzag in its web, egg sac, range, and whether its bite iOrb WeaversSpined Micrathena (Micrathena gracilis)Identify the spined micrathena (Micrathena gracilis): its black-and-white spined abdomen, the dense daytime orb web it rebuilds each morningOrb WeaversArrowhead (Verrucosa arenata)Identify the arrowhead orb weaver (Verrucosa arenata): the white triangle, its head-up posture in the web, range, habitat and whether the bi

Nursery Web (Pisauridae)

Nursery Web SpidersDark Fishing (Dolomedes tenebrosus)Identify the dark fishing spider (Dolomedes tenebrosus): size, chevron markings, where it lives in North America, and whether its bite is daNursery Web SpidersSix-spotted Fishing (Dolomedes triton)Identify the six-spotted fishing spider (Dolomedes triton): size, stripes, how it walks on water, its range, and whether its bite is dangeroNursery Web SpidersWhite Banded Fishing (Dolomedes albineus)Identify the white banded fishing spider (Dolomedes albineus): the white face band, mossy green colour, its swamp-forest range and whether i

Jumping (Salticidae)

Jumping SpidersBold Jumping (Phidippus audax)Identify the bold jumping spider (Phidippus audax): size, the white triangle, green jaws, how it hunts without a web, and whether its bite iJumping SpidersTan Jumping (Platycryptus undatus)Identify the tan jumping spider (Platycryptus undatus): flattened body, wavy abdominal pattern, size, where it lives and whether its bite isJumping SpidersApache Jumping (Phidippus apacheanus)Identify the Apache jumping spider (Phidippus apacheanus): orange-red body, black legs, velvet-ant mimicry, arid-country range and whether t

Cellar (Pholcidae)

Cellar SpidersLong Bodied Cellar (Pholcus phalangioides)Identify the long-bodied cellar spider (Pholcus phalangioides): size, legs, web and eggs, plus the truth about the daddy-long-legs venom myt

Wolf (Lycosidae)

Wolf SpidersTigrosa GeorgicolaIdentify Tigrosa georgicola, a dark wolf spider of southeastern US woodland floors: size, stripe, egg sac, hunting behaviour and how harmlesWolf SpidersRabid Wolf (Rabidosa rabida)Identify the rabid wolf spider (Rabidosa rabida) by its stripes and size, and learn about its egg sac, range in the eastern US and its harml

Living with Missouri's spiders

Living comfortably in recluse country comes down to a short list of habits:

• Shake out shoes, gloves and clothing that has been stored or left on the floor.
• Swap cardboard boxes for sealed plastic bins, which recluses cannot colonise.
• Keep beds away from walls and bedding off the floor.
• Wear gloves for woodpiles, glade rock, meter boxes and barn lumber.
• Use sticky traps along baseboards to measure a building's real recluse numbers before treating it.
• Vacuum webs and egg sacs rather than spraying, and leave wandering male tarantulas alone in autumn.

For a very similar fauna immediately south, see Arkansas.