Poisonous Spiders Commonly Found in Pennsylvania
Pennsylvania's forests, parks, and backyards are home to several species of spiders that are capable of inflicting medically significant bites on humans. While the majority of spiders in Pennsylvania are not considered dangerous, there are a few venomous species that do pose a risk.
Brown Recluse Spider
The brown recluse spider (Loxosceles reclusa) is one of the most feared spiders in North America. Despite their name, brown recluse spiders are found well beyond the Midwest and occur in parts of Pennsylvania. These spiders have a violin-shaped marking on their cephalothorax and can be identified by their six equal-sized eyes arranged in three pairs.
Brown recluse venom contains harmful cytotoxins that can cause necrosis and systemic symptoms in humans. Their bites often go unfelt initially and then progress to pain and tissue damage around the bite site. Severe bites lead to centralized red and purple lesions that require excision by surgeons.
Black Widow Spider
The notorious black widow spider resides in the southern and western regions of Pennsylvania. Black widows (Latrodectus mactans) are long-legged spiders with a glossy black body and prominent red hourglass marking on the underside of their large rounded abdomen.
Female black widow bites can cause severe muscle aches, nausea, and increased blood pressure. Their neurotoxic venom is rarely fatal to healthy adults but poses a higher risk to the elderly, young children, and those with compromised immune systems. Luckily, prompt medical care and the availability of antivenom make fatalities exceedingly rare.
Yellow Sac Spider
Yellow sac spiders (Cheiracanthium inclusum) are one of the most common spiders encountered by Pennsylvania residents. These spiders are pale yellow to greenish-yellow in color and have a faint darker stripe running down the top of their oval-shaped abdomen.
The bites of yellow sac spiders cause mild skin irritation in most cases. On rare occasions, their venom induces itchy red welts or small necrotic ulcers at the bite site. Their bites are seldom medically significant, but in sensitized individuals, the venom can trigger severe reactions.
Running Crab Spider
Running crab spiders comprise several quick-moving species that do not build webs to catch prey. These include the six-spotted fishing spider (Dolomedes triton), spined micrathena (Micrathena gracilis), and multiple Misumena species.
Most running crab spiders found in Pennsylvania have bites comparable to bee stings. They typically only bite when pressed against the skin and cause mild irritation and swelling. Nonetheless, their speed and tendency to hide amongst vegetation leaves the potential for accidental bites.
Signs of a Spider Bite
Many suspected spider bites are actually bites or stings from other arthropods like bed bugs, fleas, ticks, and wasps. However, characteristic signs of true spider bites in Pennsylvania include:
- Two small puncture wounds from the spider's fangs
- Redness, swelling, and pain spreading from the bite site
- Itchy rashes, welts, or blisters on the surrounding skin
- Flu-like symptoms if bitten by a recluse or widow (rare)
These symptoms usually manifest within 2 to 8 hours of being bitten. Most heal fully over time, but bites from venomous species often require medical intervention to prevent further skin damage and relieve intense pain.
First Aid for Spider Bites
If bitten by a spider in Pennsylvania, proper first aid steps include:
- Wash the bite area gently with antibacterial soap and water
- Apply an ice pack wrapped in cloth to reduce swelling and inflammation
- Keep the bite below heart level to slow venom circulation
- Call a doctor if systemic symptoms appear or increase dramatically
Refrain from squeezing or draining the bite site and never apply tourniquets, cut the wound, or attempt to suck out the venom. Bring the offending spider with you in a sealed container if captured for identification purposes.
Preventing Spider Bites
Practicing smart spider avoidance and proofing homes against infestations are the best ways Pennsylvania residents can prevent bites. Useful tips include:
- Shaking out shoes, gear, and clothing before each use
- Wearing gloves, long sleeves, and pants when gardening
- Clearing clutter that offers hiding spots indoors
- Sealing cracks in foundations and walls
- Installing nightlights and motion sensor lights outdoors
- Keeping beds pulled away from walls and tucking in sheets
Being vigilant outdoors and understanding venomous species that pose threats in the area make avoiding spider bites much easier. Always seek medical care right away if bitten by spiders with warning colors like red, yellow, and black.
FAQs
What are some of the most poisonous spiders found in Pennsylvania?
Some of the most venomous spiders in Pennsylvania include the black widow spider, brown recluse spider, yellow sac spider, and the six-spotted fishing spider (also known as the six-spotted running crab spider). Black widow and brown recluse bites usually require medical attention.
Where in Pennsylvania are brown recluse spiders found?
Brown recluse spiders are most often found in south-central Pennsylvania, but there have been isolated populations documented in areas surrounding Philadelphia and Pittsburgh. They tend to inhabit dry, abandoned structures.
How dangerous is a bite from a yellow sac spider?
The majority of yellow sac spider bites cause mild skin irritation with redness, itching, and swelling around the bite site. However, in rare instances they have been known to cause skin lesions or necrosis. They are generally not considered medically significant.
How fast do symptoms typically appear after being bitten by a venomous spider?
Symptoms of a bite from venomous spiders like the black widow or brown recluse usually occur within 2 to 8 hours after being bitten. A blistering sore or lesion may develop at the bite site along with system-wide symptoms in severe envenomizations.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.
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