DNR: This online guide is not an inclusive list of spiders found in Maryland, but it contains many commonly encountered spiders. There are over 40,700 species of spiders worldwide and hundreds of species in Maryland.
This page lists 13 spiders.
1 is venomous by official accounts, and 1 mildly venomous.
Not every species: no complete official list of Maryland spiders exists, so this page covers the ones state and Extension sources name. How lists are built.
Which spiders can hurt you
Official sources single out these spiders in Maryland, in their own words:
Not native. “Brown recluse spiders are not native to Maryland, but on very rare instances they can stow away on packages from the Midwest and the Southwest where the Brown recluses are more common.” DNR
Venom: “The Black Widow spider is the only venomous spider native to Maryland.” (Maryland Poison Center)
Habitat: These spiders are most often found in basement window wells, beneath lawn benches or porches, and in garages, tool sheds, old lumber piles, rock piles, trash piles, and water meters. (University of Maryland Extension)
Venom: “Despite sensationalist reports, they are harmless to people as they are reluctant to bite and, if bites do occur, the venom is weak and not medically important.” (University of Maryland Extension)
No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
Size
Females 3/4 to 1 inch long, not counting legs (Missouri); 19 to 28 mm (Penn State); Texas A&M says the female body is more than 1 inch. Males about 1/4 inch (Missouri); 5 to 8 mm (Penn State).
How to recognize it
Round web about 2 feet across, built only by females; the spider rests head-down at the center, where a zigzag silk band (stabilimentum) runs vertically.
Abdomen an elongated oval, pointed at the rear, with two humps (shoulders) at the front.
Males are much smaller than females and rarely noticed.
No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
No confirmed photo of Micrathena spiders
Micrathena spiders
Not stated
Venom
No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
No confirmed photo of Nursery web spider
Nursery web spider
Pisaurina spp.
Not stated
Venom
No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
No confirmed photo of Wolf spiders
Wolf spiders
Not stated
Venom
No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
When spiders are active in Maryland
Records of spiders in Maryland peak in May to June and August to September. They show when people record spiders, not how many there are (about month bars).
JanFebMarAprMayJunJulAugSepOctNovDec
5,615 records of spiders in Maryland by month (GBIF, CC0 and CC BY records).
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.
What official sources say
Are there brown recluse spiders in Maryland?
Not established. DNR says they are not native but on very rare occasions stow away on packages. DNR
“Brown recluse spiders are not native to Maryland, but on very rare instances they can stow away on packages from the Midwest and the Southwest where the Brown recluses are more common.”
About this list
The species list comes from Common Maryland Spiders; Common Spiders of Maryland (Wild Acres) (Maryland Department of Natural Resources (DNR), March 2019; Internet Archive capture 2025-12-25). 13 more entries come from other official sources named on each card.
Venom labels come only from official sources and link to them; "Not stated" never means harmless. How labels work.
Common Maryland Spiders. Maryland Department of Natural Resources (DNR). archived copy, captured December 25, 2025; checked November 3, 2026.Archived copy. Quoted passages (2)
“This online guide is not an inclusive list of spiders found in Maryland, but it contains many commonly encountered spiders. There are over 40,700 species of spiders worldwide and hundreds of species in Maryland.”
“Many of the spiders in Maryland possess venom, but the black widow is the only native Maryland spider that is dangerous to people.”
Spiders in Maryland. University of Maryland Extension. updated February 3, 2025; checked November 3, 2026.Quoted passages (2)
“Despite sensationalist reports, they are harmless to people as they are reluctant to bite and, if bites do occur, the venom is weak and not medically important.”
“The black widow female becomes mature in late summer and fall.”
“Brown recluse spiders are not native to Maryland, but on very rare instances they can stow away on packages from the Midwest and the Southwest where the Brown recluses are more common.”
