Trachelas spiders, often known as broad-faced sac spiders, are common in many environments, particularly within homes during cooler autumn months. Encounters with these spiders often lead to questions about their bites. This article provides clear information on Trachelas spiders and their interactions with humans.
Identifying Trachelas Spiders
Trachelas spiders have distinct physical characteristics. They typically exhibit a bi-colored body, with a solid, often shiny, dark brown or reddish cephalothorax. The abdomen, in contrast, is usually a duller tan or gray color and lacks any noticeable patterns. Adult females of this species measure approximately 7 to 10 millimeters in body length, while males are slightly smaller, around 5 to 6 millimeters.
Their legs are commonly tan, brown, or reddish, with the front pair appearing notably darker than the others. These spiders have eight eyes, which are widely spaced, a feature distinguishing them from species like the woodlouse hunter, which has six grouped eyes. Trachelas spiders do not construct webs to capture prey; instead, they are nocturnal hunters that create silken sacs for daytime retreat.
Toxicity and Venom
Trachelas spiders are venomous, but their venom is not considered medically significant to humans. The primary purpose of their venom is to immobilize insect prey. When a bite occurs, the venom typically causes only mild, localized discomfort rather than severe systemic reactions.
Bites from Trachelas spiders are usually defensive, occurring when the spider feels threatened or is accidentally compressed against the skin. Unlike the venom of some other spider species, Trachelas venom does not typically lead to necrosis.
Bite Symptoms
A Trachelas spider bite is often initially painful, comparable to a bee or wasp sting. Following the bite, individuals commonly experience localized reactions at the site. These reactions typically include pain, redness, and swelling.
While most reactions are confined to the bite area, some individuals with sensitivities to arthropod venoms might experience a slightly more pronounced response. The red mark that forms usually resolves within a day. A notable concern associated with these bites is the potential for secondary bacterial infection.
Post-Bite Care
If a Trachelas spider bite occurs, first aid measures can help manage symptoms. Begin by thoroughly cleaning the wound with mild soap and water. Applying an antibiotic ointment three times daily can help deter bacterial infection.
To reduce pain and swelling, apply a cool compress or ice pack to the affected area for about 15 minutes each hour. Elevating the bitten limb, if possible, can also help minimize swelling. Over-the-counter pain relievers can manage discomfort, and antihistamines may alleviate itching. Seek medical attention if symptoms worsen, signs of infection (like increased redness or pus) appear, or if an allergic reaction is suspected.