Encounters with white spiders often cause apprehension. While their pale appearance might trigger concern, most spiders, regardless of coloration, are generally harmless to humans. Many spiders exhibit white or off-white tones as natural camouflage or at different life stages. This guide clarifies which white spiders are benign and which might warrant more caution, distinguishing between common fears and actual risks.
Common Harmless White Spiders
Many white or pale spiders encountered in homes and gardens pose little to no threat. Crab spiders (family Thomisidae) are frequently white, yellow, or green, blending seamlessly with flowers and foliage where they ambush prey. These spiders have a distinctive crab-like appearance, with legs extended sideways. While they possess venom, it is primarily used to subdue insects and is not medically significant for humans. A bite from a crab spider is rare and usually results in only mild, localized irritation, similar to a bee sting.
Sac spiders (genus Cheiracanthium) also appear pale, with some species having a creamy or pale yellow body. These active hunters do not build large webs, often found in silken retreats in room corners or under outdoor objects. Their bites can be painful, causing a burning sensation, redness, and swelling, but symptoms are mild and resolve within a few days. Ghost spiders (family Anyphaenidae) are also pale or cream-colored. These fast-running spiders are harmless, and their bites are comparable to a pinprick or bee sting, rarely causing more than temporary marks or minor swelling.
Identifying Potentially Harmful White Spiders
While most white spiders are harmless, a few species that can appear pale or off-white at certain life stages possess medically significant venom. Immature black widow spiders (Latrodectus species) are lighter than adults, displaying orange, brown, and white markings before maturing to their characteristic glossy black with a red hourglass. The classic red hourglass marking, on the underside of the female’s abdomen, might be present but less distinct, or appear as red or yellow spots. Black widows prefer dark, undisturbed areas like woodpiles, garages, and basements. Their bites, though rare, can cause severe pain, muscle cramps, nausea, and sweating, requiring immediate medical attention.
Certain recluse spiders (Loxosceles species), such as the brown recluse, can also range in color from whitish to dark brown or grayish-black. The brown recluse is identified not by color alone, but by a distinct violin-shaped marking on its back, with the “neck” of the violin pointing towards the spider’s rear. Another key identifier is their eye arrangement: recluse spiders have six eyes arranged in three pairs, unlike most spiders that have eight eyes. Their bites can lead to a sore with a blue or purple center, and in some cases, a necrotic wound that can take months to heal. These spiders are commonly found in the southern and central United States, preferring undisturbed, dark places.
What to Do if Bitten
If you suspect a spider bite, especially from a potentially harmful species, immediate first aid is important. Clean the bite area gently with mild soap and water. Applying a cool compress or ice pack to the bite for 15 minutes each hour can help reduce pain and swelling. Elevating the affected area, if possible, can also help minimize swelling. Over-the-counter pain relievers can be used for discomfort, and an antihistamine might help with itching.
It is important to seek medical attention immediately if you suspect a bite from a black widow or brown recluse spider, or if you experience severe symptoms. Symptoms warranting prompt medical evaluation include severe pain, abdominal cramping, difficulty breathing or swallowing, spreading redness or red streaks from the bite, fever, chills, nausea, vomiting, or a growing wound at the bite site. If safely possible, try to capture the spider for identification, as this can assist medical professionals in providing appropriate treatment. However, prioritize your safety and do not risk further bites.