Last checked November 3, 2026 against official sources.
This page lists 10 spiders. 5 are venomous by official accounts. 5 are nonnative.
Not every species: no complete official list of Louisiana spiders exists, so this page covers the ones state and Extension sources name. How lists are built.
Official sources single out these spiders in Louisiana, in their own words:
Medically significant venomous spider (LSU AgCenter). “Recluse spiders are among the few medically significant spiders in the southern U.S. (widow spiders, Latrodectus spp., are the other).” LSU AgCenter
Venomous. “Black widow bites pose a significant medical event that require prompt treatment.” LSU AgCenter
Venomous widow spider. “Brown widows are less of a medical threat to humans than black widows.” LSU AgCenter
Painful bite and irritating urticating hairs when cornered (LDWF). “Although much more prone to flee and hide than attack, when cornered, this species can inflict a painful bite and may fling urticating hairs, which are irritating to skin and dangerous if cast into the eyes.” LDWF species profile: Texas Brown Tarantula
Venomous species first, then A to Z. Do not handle them.
Venom: “Recluse spiders are among the few medically significant spiders in the southern U.S. (widow spiders, Latrodectus spp., are the other).” (LSU AgCenter)
Latrodectus geometricus
Venom: “Even in rare cases of bites, the amount of venom injected is less than with other species and usually results in milder symptoms.” (LSU AgCenter)
Venom: “Recluse spiders are among the few medically significant spiders in the southern U.S. (widow spiders, Latrodectus spp., are the other).” (LSU AgCenter)
Latrodectus variolus
Venom: “…if contact is made they are capable of delivering a potent venom with both local and systemic neurotoxic effects.” (LSU AgCenter)
Latrodectus mactans
Venom: “…if contact is made they are capable of delivering a potent venom with both local and systemic neurotoxic effects.” (LSU AgCenter)
Heteropoda venatoria
Plexippus paykulli
Crossopriza lyoni
Kukulcania hibernalis
Aphonopelma hentzi
Habitat: In Louisiana, it seems to prefer sandy uplands where it burrows under rocks and logs (LDWF species profile: Texas Brown Tarantula)
Brown widow spider Venomous
Black widow (adult) Venomous
Adult female black widows are usually shiny black with red markings; very dark brown widows are flat black. The brown widow hourglass is usually orange to yellow-orange, but do not rely on color alone: UF/IFAS shows a brown widow with a red hourglass, Clemson says usually orange or red-orange, and black widow markings vary (northern black widows have two red spots; a western black widow's red can be almost imperceptible or absent). Brown widow egg sacs are spiky; Clemson (2003) and UF/IFAS Sarasota describe black widow sacs as smooth, and Clemson (2026) says the southern black widow's sac has a single small point.
Photos show typical adults; individuals vary. Never get close to compare.
Records of spiders in Louisiana peak in April to August. They show when people record spiders, not how many there are (about month bars).
Call 911 or Poison Help at 1-800-222-1222 right away. Poison Help connects you to your local poison center, any time of day.
Yes. LSU AgCenter: common in the northern half of the state, exceedingly uncommon in southern Louisiana. LSU AgCenter
“In Louisiana, brown recluses are common in the northern half of the state approximately north of a line drawn through Alexandria.”
Yes. LSU AgCenter: southern and northern black widows both occur in Louisiana; the introduced brown widow is also present. LSU AgCenter
“Both the northern and southern black widow overlap in distribution in the southern U.S., including Louisiana.”
Venom labels come only from official sources and link to them; "Not stated" never means harmless. How labels work.
"Nonnative" and "Invasive" follow the wording of the source list. See invasive species in Louisiana.
“Recluse spiders are among the few medically significant spiders in the southern U.S. (widow spiders, Latrodectus spp., are the other).”
“In Louisiana, brown recluses are common in the northern half of the state approximately north of a line drawn through Alexandria.”
“…if contact is made they are capable of delivering a potent venom with both local and systemic neurotoxic effects.”
“Black widow bites pose a significant medical event that require prompt treatment.”
“Both the northern and southern black widow overlap in distribution in the southern U.S., including Louisiana.”
“Even in rare cases of bites, the amount of venom injected is less than with other species and usually results in milder symptoms.”
“Egg sacs of brown widow spiders are distinct and diagnostic for the presence of brown widows, even in the absence of the spiders themselves.”
“They are round, formed from silk and typically are around 10 mm in diameter. The surface has a regular arrangement of blunt silken spikes or tubercles”
“Brown widows are less of a medical threat to humans than black widows.”
“Adults females are medium to large 0.3-0.5 inches (8-12 mm in body length), tan to dark brown spiders, with globular abdomens that are dull or slightly shiny in surface luster and covered with fine velvet hairs.”
“Although much more prone to flee and hide than attack, when cornered, this species can inflict a painful bite and may fling urticating hairs, which are irritating to skin and dangerous if cast into the eyes.”
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