Most arthropod pests are nothing more than a nuisance when they enter homes and buildings, especially in the northeast US where most insect and arachnid species are not considered a medical threat to residents. Of course, there are exceptions like the European fire ant (Myrica rubra) that has been responsible for medically serious envenomation incidents, some of which caused victims to experience potentially fatal anaphylactic episodes. These non-native ants have established an invasive habitat in the northeast US where the species is considered a growing public health threat. While venomous ant species are largely absent from the northeast, other venomous pests in the order Hymenoptera commonly nest on residential and commercial properties in the region. These pests include yellow jackets, paper wasps, and solitary wasp species like cicada killer and mud dauber wasps. Unfortunately, a particular spider species that is notorious for inflicting potentially deadly bites to humans is occasionally found within and around structures in Massachusetts.
The vast majority of spider species in the US are far from aggressive, and they will readily flee toward the nearest safe harborage when approached by humans. Even the unusually large and tarantula-like Carolina wolf spider that frequently enters Massachusetts homes seems to have a paralyzing fear of humans. Yellow sac spiders (Cheiracanthium spp.), on the other hand, are one of the most commonly managed indoor spider pests in the northeast, and they are unique for being the only spiders that aggressively bite humans within homes without provocation. The most dangerous spider species found in Massachusetts is the northern black widow (Latrodectus variolus). Although it is often claimed that these spiders are almost never encountered within and around homes in Massachusetts, a 5 year old Mendon girl who was hospitalized three years ago as a result of sustaining a black widow bite on her porch would probably disagree. 70 to 80 percent of black widow bites cause local pain and swelling, and six percent of black widow bites reported annually in the country were proven to be potentially fatal before life saving treatment was administered to envenomation victims.
Have you ever spotted a yellow-sac spider within your home?