Metaltella simoni, or the “cribellate spider,” as the species is more commonly known, is native to Argentina, southern Brazil, and Uruguay, but the species was discovered in the US for the first time back in 1944 when specimens were recovered from Harahan, Louisiana. Not long afterward, large cribellate spider populations were found in east Baton Rouge, New Orleans, and St. Tammany Parishes. This species has been documented as dwelling in natural undisturbed environments, but most records describe the cribellate spider’s propensity to live alongside humans within homes and buildings. Today, these spiders are very common indoor pests in Louisiana, and while they are not considered medically significant, their intimidating appearance often gives homeowners a scare.

The cribellate spider can be recognized for its dark exterior and its .25 to .37 inch long body, which does not include their long legs. Adult males are slightly smaller than females, and they possess legs that are yellowish-orange in color, while adult females have legs that are dark brown in color. Females and offspring spin webs that are somewhat tattered and are similar in appearance to the webs constructed by southern house spiders, only smaller. Females and offspring establish harborages beneath logs, behind tree bark, beneath wood piles, and in boxes, dark corners, storage rooms, and beneath objects that are attached to the female’s silk webbing. Males are almost always wandering around in search of prey, and they will readily enter homes to pursue prey or to secure refuge from harsh climatic conditions.

While these synanthropic spiders are known for appearing in Louisiana homes all year round, researchers are mostly unfamiliar with the cribellate spider’s life history and biology. However, it is known that adults of this species possess oversized chelicerae and fangs, which makes them competent predators, as well as pests that can inflict painful bites on human skin when properly motivated. The cribellate spider’s long and dark legs make specimens easy to spot on indoor walls and ceilings, and this species is commonly mistaken for the similar looking brown recluse spider species.

Have you ever sustained a spider bite in your home?