Bugs and spiders in Maryland

The spotted lanternfly is the most-recorded species in Maryland by a clear margin, with Asian lady beetles and eastern carpenter bees next. Brown marmorated stink bugs and jumping spiders follow. Three Be-careful or Get-advice species, the southern black widow, the brown recluse and the red imported fire ant, have records here but are not known to live in the state.

Get advice if bitten

These are found in Maryland. If you think one bit or stung you, call Poison Help at 1-800-222-1222; call 911 for trouble breathing or swelling.

Common in Maryland

Established here or recorded often, most-recorded first.

Spotted lanternflyHarmlessEstablished · 12,551 recordsAsian lady beetleBe carefulCommon · 9,606 recordsEastern carpenter beeBe carefulCommon · 6,742 recordsBrown marmorated stink bugHarmlessCommon · 3,101 recordsBold jumping spiderHarmlessCommon · 3,046 recordsTan jumping spiderHarmlessCommon · 2,806 recordsYellow garden spiderBe carefulCommon · 2,675 recordsBoxelder bugHarmlessCommon · 2,318 recordsDark fishing spiderBe carefulCommon · 2,068 recordsEastern yellowjacketBe carefulCommon · 1,850 recordsSpotted orbweaverHarmlessCommon · 1,756 recordsBlack carpenter antHarmlessCommon · 1,292 recordsPill bugHarmlessCommon · 1,031 recordsVaried carpet beetleHarmlessCommon · 884 recordsGreenhouse millipedeHarmlessCommon · 873 recordsLone star tickGet adviceEstablished · 866 recordsEuropean earwigHarmlessCommon · 849 recordsGreenhouse camel cricketHarmlessCommon · 828 recordsHouse centipedeBe carefulCommon · 772 recordsAmerican dog tickGet adviceEstablished · 738 recordsEuropean paper waspBe carefulCommon · 704 recordsWestern conifer seed bugHarmlessCommon · 690 recordsOdorous house antHarmlessCommon · 610 recordsNorthern black widowGet adviceEstablished · 459 recordsWoodlouse spiderHarmlessCommon · 447 recordsBroad-faced sac spiderBe carefulCommon · 385 recordsPavement antHarmlessCommon · 382 recordsBlacklegged tickGet adviceEstablished · 363 recordsOriental cockroachBe carefulCommon · 259 recordsCommon house spiderHarmlessCommon · 235 recordsZebra jumping spiderHarmlessCommon · 189 recordsIndianmeal mothHarmlessCommon · 188 recordsLong-bodied cellar spiderHarmlessCommon · 162 recordsAmerican cockroachBe carefulCommon · 131 recordsBarn funnel weaverHarmlessCommon · 80 recordsFruit flyHarmlessCommon · 69 recordsGerman cockroachBe carefulCommon · 63 recordsHouse flyBe carefulCommon · 26 recordsYellow fever mosquitoBe carefulEstablished (parts of the state) · 19 recordsHouse mosquitoBe carefulEstablished · 9 recordsBrown dog tickGet adviceEstablished

What to watch for in Maryland

Ticks are the main concern. The lone star tick and the American dog tick are the most-recorded, followed by the blacklegged tick, and the brown dog tick is established as well. The lone star tick can spread ehrlichiosis and is linked to alpha-gal syndrome, a red-meat allergy, and the blacklegged tick can spread Lyme disease. The northern black widow is established here too, and a bite from an adult female can cause spreading pain and cramps, so get medical advice right away.

Records of the southern black widow and the brown recluse exist, but neither is known to live in Maryland, and such sightings are often misidentified spiders or hitchhikers. Most brown recluse bites heal on their own, but call Poison Help at 1-800-222-1222 if a bite worries you. The yellow fever mosquito is established in parts of the state. Cockroaches are Common, with oriental, American and German all listed, and yellowjackets and European paper wasps are the common stingers.

Through the year

Spring
Eastern carpenter bees are busiest in April to June, lone star tick adults are active, and black carpenter ants indoors this early may signal a nest inside the house.
Summer
Spotted lanternfly nymphs are out through summer and adults appear in July, while mosquitoes bite in earnest from about June.
Fall
Boxelder bugs, brown marmorated stink bugs and Asian lady beetles move in between late August and November, and spotted orbweavers and yellow garden spiders leave their webs up.
Winter
Greenhouse camel crickets and house centipedes are the usual winter finds, and a few stink bugs and lady beetles wander out on mild days.

Seen now and then

Recorded a few times; often brought in on plants, firewood or luggage.

Recorded, not established

Range maps don't place these here, but people have recorded them. Usually hitchhikers.

Lists come from research-grade iNaturalist sightings (Maryland: 882,722 arthropod records) and, for dangerous species, published range maps. A species with few records may be a hitchhiker. Counts pulled Oct 18, 2026.

Identify a bug in Maryland