Maryland homeowners see dozens of spider species throughout the year, from tiny jumping spiders to large orb weavers. Knowing which ones live here helps you decide what action to take. This guide covers the most common spiders in Maryland homes and how to manage them.
Common Spiders in Maryland
Maryland has hundreds of spider species. The University of Maryland Extension tracks them across the state. Most arrive in homes by accident while chasing insects or looking for shelter. Only two species can cause medical problems.
In wooded areas like Mt. Vernon, spider numbers build up fast in home eaves during warm months. They’re drawn to the flying insects around exterior lights.
The Maryland Biodiversity Project tracks hundreds of species from coastal marshes to mountain forests. The most common in homes are black widows, wolf spiders, house spiders, jumping spiders, and orb weavers. For more on spider identification, see our pest library.
Maryland Spider Species Guide
Black Widow Spider
Maryland’s only medically important spider. Females are shiny black with red hourglass markings underneath (the northern species may show broken red spots instead). About half an inch long.
They build messy webs in wood piles, shed corners, and basement window wells. Maryland DNR notes they hang upside-down and rarely bite unless pressed against skin. Black widow bites can cause muscle cramps and pain. If you find them near play areas or pet zones, call a pro.
Wolf Spider
Brown to gray hunters that range from 1/4 inch to over an inch long. You’ll recognize them by their eye shine at night. Females carry egg sacs on their abdomens. They don’t build webs. Instead, they chase down prey on the ground.
Wolf spiders often run across basement floors in fall looking for winter shelter. They rarely bite and aren’t dangerous. Active March through October.
House Spiders and Cellar Spiders
House spiders build tangled webs near windows and in corners. They’re small and mottled gray. Cellar spiders (“daddy long-legs”) have very long legs and build webs in damp basements and crawl spaces. Both are harmless and rarely bite.
Jumping Spiders
Compact, fuzzy spiders with great eyesight. They don’t build webs but stalk prey on walls and window sills. The bold jumping spider (Phidippus audax) has a black body with bright mouthparts. Completely harmless.
Orb Weavers and Garden Spiders
The yellow garden spider (Argiope aurantia) builds huge orb webs up to 2 feet across with zig-zag patterns. Females can have 2.5-inch leg spans. Found throughout Maryland from gardens to porches. Harmless despite their size.
Fishing Spiders and Joro Spider
The dark fishing spider is one of Maryland’s biggest native spiders. It lives near water and sometimes wanders into homes during dry spells. Harmless.
Maryland’s first Joro spider was found in Howard County in September 2024. Maryland DNR says this large, colorful species builds golden orb webs and eats stink bugs. Its spread across the state is being watched by researchers.
Venomous vs Harmless
Only two species in Maryland can cause medical issues: the southern and northern black widow. Even these rarely bite and only do so when trapped or pressed.
University of Maryland Extension confirms that brown recluse spiders can’t survive Maryland winters. Most “recluse” reports are misidentified wolf or house spiders.
Yellow sac spiders can bite with local pain and mild swelling, but nothing like a true recluse bite. The myth about cellar spiders being “deadly but unable to bite” is completely false.
Where Spiders Hide
Here’s a look at some of the spiders you may find in and around Maryland homes.
Indoor hotspots: basement corners, crawl spaces, cluttered storage, and window areas.
Outdoor by region:
- Coastal plain: under deck furniture, around shoreline structures
- Piedmont suburbs: shrubs touching siding, porch lights, garden supports
- Western highlands: stone foundations, wood piles, leaf litter
Moisture problems attract the insects that spiders eat. Fix drainage, gutters, and damp basements to reduce spider numbers.
Seasonal Patterns
- Spring (March-May): First wolf spiders and jumping spiders appear. Black widow mating begins.
- Summer: Peak web season. Garden spiders and orb weavers build their biggest webs.
- Fall (September-October): Most indoor spider sightings as males wander looking for mates. Yellow sac spiders move inside.
- Winter: Most species go dormant outdoors. Cellar and house spiders stay active in heated homes. Egg sacs overwinter in eaves.
Prevention
The best approach: remove existing webs and apply non-repellent treatments along your foundation. This handles current spiders and keeps new ones from moving in.
For step-by-step help, see our spider removal guide.
When to Call a Pro
Call a professional when black widows keep showing up near kids or pets, or when spider problems come back despite sealing and cleaning. This often points to moisture issues or entry points that need a pro’s eye.
Our approach includes tri-annual visits (three times per year) to maintain exterior treatments and clear webs from eaves and porches. For homeowners in College Park and nearby areas, we tailor service to local spider patterns and seasonal activity.
If you need spider help, call us at 703-683-2000 or email info@bettertermite.com.
