The brown recluse spider has become notorious for inflicting bites to humans that sometimes cause tissue necrosis, dangerous allergic reactions, and/or systemic symptoms like fever, chills, vomiting and diarrhea. The brown recluse spider (Loxosceles reclusa) is the most widespread and commonly encountered recluse spider species in the US, and they are abundant throughout Louisiana. The US is home to 13 recluse spider species, two of which are non-native species that were inadvertently transported into the country. One of these non-native species, the Mediterranean recluse, has become established in New Orleans and other urban areas in southern Louisiana.
Several laboratory studies on recluse spider venom, and multiple case studies on recluse spider bite victims have found that all 13 recluse spiders in the country are capable of inflicting medically significant bites that produce the same symptoms. The brown recluse is responsible for inflicting the vast majority of reported recluse bites, as the other species, with the exception of the Mediterranean recluse, prefer to dwell in undisturbed areas of the natural environment where they are very rarely encountered by humans. While the Mediterranean recluse is not widespread, it is similar to the brown recluse in that it is an urban-dwelling species that benefits from living in close association with humans. Mediterranean recluse infestations are becoming more common, as a recent nationwide survey of pest management professionals revealed that the Mediterrranean recluse was the most commonly controlled spider pest within homes during the 2016 year.
Brown recluse spiders and the danger they pose to humans started to become well known to the public during the 1950s when the medical community took note of several fatal brown recluse envenomation incidents. Between 1983 and 2009, 42,544 brown recluse spider bites were reported to the American Association of Poison Control Centers. Of these thousands of brown recluse bite victims, only seven died as a result of envenomation. Brown recluse spiders are among the top five most commonly controlled indoor spider species in the US, and their presence within a home may go unnoticed for a time due to their habit of hiding beneath clutter in storage rooms, attics, garages, and basements. Infestations tend to grow more extensive over time, and eventually, their indoor population increases to the point where residents begin to spot the spiders in open living areas during the day. Although brown recluse spiders very rarely inflict deadly bites, residents should not attempt to eliminate the spiders from homes themselves, as most bites occur indoors. Most infestations require professional pest control intervention.
Have you ever found brown recluse spiders in your home?