The Metaltella simoni spider, a type of hacklemesh weaver, is frequently encountered. These spiders are not considered dangerous to humans, despite their sometimes startling appearance. While all spiders possess venom, the venom of M. simoni is not medically significant to people.
Assessing the Bite Risk and Venom Potency
Metaltella simoni is venomous, like nearly all spiders, but its venom is specifically adapted to subdue its small arthropod prey. The neurotoxins present in the venom are not potent enough to cause serious harm to a person.
Bites from M. simoni are extremely rare and occur only as a defensive measure, typically when the spider is accidentally trapped or squeezed against the skin. The spider does not exhibit aggressive behavior toward humans and will usually attempt to flee when disturbed. If a bite does occur, the reaction is generally mild and localized.
A bite may result in minor symptoms such as a mild burning sensation, slight pain, or localized swelling and itching at the site of the bite. These symptoms are often comparable to those experienced from a common household insect bite, like a mosquito or gnat. Medical treatment is typically not required, and any discomfort usually resolves quickly without long-term effects. The low potency of the venom means the spider poses virtually no threat to human health.
Identifying Metaltella simoni
Identifying Metaltella simoni correctly can help alleviate unnecessary fear, as it is often mistaken for other spiders. Adult females measure about 8 to 9 millimeters in body length, while males are slightly smaller, between 7 and 8.5 millimeters. The body is generally brown, tan, or gray, often with a mottled gray abdomen.
The spider’s legs and carapace can appear dark brown, though males may have a yellow to yellow-orange coloration on their legs and the rear of the carapace. A distinguishing feature is the spider’s web, which is an irregular, fluffy, or messy-looking sheet web constructed with a specialized type of cribellate silk.
Typical Habitat and Behavior
Metaltella simoni is native to South America (Argentina, Brazil, and Uruguay), but has established a stable presence in parts of North America, including coastal regions of the United States and Canada. The spider prefers environments that are dark and damp.
Common outdoor habitats include under logs, rocks, boards, leaf litter, and in crevices near the ground. Indoors, they are considered synanthropic, often constructing their webs in secluded, undisturbed areas such as basements, garages, and storage spaces. They are nocturnal hunters, using their hacklemesh webs to ensnare wandering insects.
Safe Removal and Prevention
If an individual Metaltella simoni spider is found inside the home, the safest and most humane method for removal is the cup-and-paper technique. This involves placing a glass or clear container over the spider and then carefully sliding a stiff piece of paper underneath to trap it inside. The spider can then be safely released outdoors in a sheltered area away from the home.
Prevention focuses on eliminating conditions that attract the spiders and sealing entry points. Reducing clutter in storage areas removes potential hiding spots. Sealing cracks and gaps around doors and windows limits access from the outside. Controlling other household insects, which serve as the spider’s food source, will also make the environment less appealing.