Black widow and brown recluse spiders are currently recognized as being the only two groups of spiders in the United States that have the potential to inflict medically significant bites to humans. However, both black widows and brown recluse spiders are not each their own species; instead, each of these spiders consists of numerous species that span the entire US. For example, widow spider species include northern, southern and western black widows, just to name a few. But their currently exists 11 documented native recluse species as well as two non-native recluse species in the US. The name “brown recluse” is often applied to all recluse species, but in truth, the term “brown recluse” is a common nickname for only one recluse species, L. reclusa. The state of Louisiana is home to two recluse species, one of which is native, the other of which is non-native. These two species are the brown recluse and the Mediterranean recluse, respectively.

Both the brown recluse and the mediterranean recluse are, as you can guess, brown-colored species that exist almost exclusively in the northern half of Louisiana. However, the mediterranean recluse, which is not as abundant as its native counterpart, has been found in New Orleans, and experts believe that this species dwells in isolated pockets throughout the state. Given the Mediterranean recluse’s tolerance of hot coastal habitats, it was not surprising to find this species in the south of the state, especially in urban environments where it arrived via cargo shipments from Europe. The brown recluse invades homes in northern Louisiana frequently, and the Mediterranean recluse is almost always found near or within homes and buildings. Despite their commonality within homes and buildings, the rate of medically significant brown recluse envenomations are surprisingly low in the state. Pest controllers in Louisiana combat indoor infestations of recluse spiders often, but they urge residents not to be alarmed the spider’s indoor presence, as they are generally shy creatures that only enter homes by accident due to their habit of wandering long distances in search of food.

Have you ever encountered a brown recluse species in your home?