Southern black widow
Latrodectus mactans
What the sources say
Venom: “The southern black widow (Latrodectus mactans) is the most notorious because of its potent venom” (NJAES)
New Jersey Spiders: Identification, Pictures & Which Bite
Last checked November 3, 2026 against official sources.
On this page
This page lists 4 spiders: 3 from NJAES's Spiders of Medical Importance and 1 named in other official sources. 2 are venomous by official accounts, and 1 mildly venomous.
Not every species: no complete official list of New Jersey 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 New Jersey, in their own words:
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Widow spiders (black widows)
Venomous. “In North America, only the widow spiders in the genus Latrodectus and the recluse spiders, in the genus Loxosceles are dangerous to humans.” NJAES
Ticks (arachnids, not spiders)
Official sources single out these ticks in New Jersey, in their own words:
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Ticks (arachnids, not spiders)
Disease. “Tick borne illnesses most commonly found in New Jersey are; Anaplasmosis, Babesiosis, Ehrlichiosis, Lyme Disease, and Rocky Mountain Spotted Fever.” NJ Poison Control Center (NJPIES), Rutgers New Jersey Medical School
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Longhorned tick
Invasive tick listed by NJDEP among the most commonly encountered invasive animals and pests with known impacts. “Longhorned Tick Haemaphysalis longicornis” NJDEP
Not confirmed here
Official sources name the recluse spiders, including the brown recluse, in connection with New Jersey, but none we use says they live there. They are not counted on this page.
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Recluse spiders, including the brown recluse (genus Loxosceles)
Presence not stated.
It is venomous, per NJAES. If you find one, do not touch it.
All 4 spiders
Venomous species first, then A to Z. Do not handle them.
No confirmed photo of Widow spiders (genus Latrodectus)
Widow spiders (genus Latrodectus)
Latrodectus spp.
- Danger to people
- “In North America, only the widow spiders in the genus Latrodectus and the recluse spiders, in the genus Loxosceles are dangerous to humans.” NJAES
- Where in New Jersey
- Every US state (Rutgers); no NJ-specific range given NJAES
What the sources say
Venom: “Black widow spiders produce venom that contains a neurotoxin.” (NJAES)
Habitat: Under stones, in firewood piles, under decks, in hollow stumps and rodent burrows; indoors in garages, basements and crawl spaces (NJAES)
Joro spider
Trichonephila clavata
- Size
- Adult female body 0.67-1.2 in (17-30 mm); legs up to 3 in long, a leg span of 3-4 in. Males are much smaller, 0.16-0.31 in (4-8 mm).
- How to recognize it
- Golden-yellow silk in very large webs, often high up between the tops of large trees; also on power lines (N.C. Extension, Henderson County)
- Adult webs have no zigzag (stabilimentum); garden spiders often have one
- One or more tiny brown males often sit in the female's web
What the sources say
Venom: “While the Jorō spider has fangs and kills its prey with venom, it is generally harmless to humans and pets, as its fangs do not easily pierce skin.” (NJAES)
No confirmed photo of Yellow sac spiders (genus Cheiracanthium)
Yellow sac spiders (genus Cheiracanthium)
Cheiracanthium spp.
- 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 New Jersey
Records of spiders in New Jersey peak in April to July and September. They show when people record spiders, not how many there are (about month bars).
If you are bitten or stung
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 black widow spiders in New Jersey?
Yes. Rutgers Cooperative Extension says widow spiders occur in every US state. It does not give a New Jersey range for each widow species. NJAES
“They occur in every state in the United States.”
Are there brown recluse spiders in New Jersey?
Rutgers says it is established over much of the southern US and recently in New York. NJAES
“…is now established over much of the southern USA, and recently in New York”
About this list
The species list comes from Spiders of Medical Importance (FS1121) (Rutgers Cooperative Extension (NJAES), May 2010). 1 more entry comes 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.
Sources
- New Jersey's Endangered, Threatened, and Special Concern Species. NJDEP Fish & Wildlife, ENSP. archived copy, captured August 25, 2026; checked November 3, 2026.
- Spiders of Medical Importance (FS1121). Rutgers Cooperative Extension (NJAES). May 2010; checked November 3, 2026.
Quoted passages (6)
“Black widow spiders produce venom that contains a neurotoxin.”
“In North America, only the widow spiders in the genus Latrodectus and the recluse spiders, in the genus Loxosceles are dangerous to humans.”
“The southern black widow (Latrodectus mactans) is the most notorious because of its potent venom”
“Brown recluse spiders posses a cytotoxin.”
“They occur in every state in the United States.”
“…is now established over much of the southern USA, and recently in New York”
- Jorō Spider: Description, Behavior, and Contrast with Similar Species (FS1386). Rutgers Cooperative Extension (NJAES). February 2026; checked November 3, 2026.
Quoted passages (1)
“While the Jorō spider has fangs and kills its prey with venom, it is generally harmless to humans and pets, as its fangs do not easily pierce skin.”
- Bites and Stings. NJ Poison Control Center (NJPIES), Rutgers New Jersey Medical School. undated page; checked November 3, 2026.
Quoted passages (1)
“Tick borne illnesses most commonly found in New Jersey are; Anaplasmosis, Babesiosis, Ehrlichiosis, Lyme Disease, and Rocky Mountain Spotted Fever.”
- Invasive Animals and Pests. NJDEP. archived copy, captured February 24, 2026; checked November 3, 2026.
Quoted passages (1)
“Longhorned Tick Haemaphysalis longicornis”
- GBIF.org occurrence records, human observations licensed CC0 1.0 or CC BY 4.0 only, accessed November 3, 2026. The datasets behind these counts are listed on our Sources page.