Public health professionals, doctors, entomologists and other experts frequently state that people living in the US should not be afraid of arthropods like insects and arachnids because the vast majority of bugs in the country are medically harmless to humans. However, this claim often conflicts with media reports that describe recent cases of medically significant human encounters with arthropod pests in the country. Examples include the migration of invasive disease-spreading mosquitoes into more northern areas, the ever increasing rate of lyme infection cases and other tick-borne diseases, rising asthma cases caused by indoor cockroach allergens, and occasional life-threatening spider bites that frequently result in necrotic wounds and/or systemic flu-like symptoms. Surprisingly, just about every arthropod-related medical threat mentioned above has occurred in Massachusetts in recent years.

Most medical professionals seem to agree that recluse spider species and widow spider species are the only two medically significant groups of spider pests inhabiting the US. Luckily, recluse spiders that are known to inflict necrotic bite wounds cannot be found in the northeast. Although the northern black widow’s habitat range extends into the northeast US and southeastern Canada, experts often insist that these notorious spiders are very rarely found anywhere in Massachusetts, let alone near homes. However, one young Massachusetts girl and her family would likely dispute this claim given the significance of their own frightening experience with black widows in the state.

During the first half of June in 2017, the girl sustained a spider bite on the deck of her Mendon home, and while at school shortly afterward, her bite wound progressed to a large purple bruise and she developed a high fever. After visiting their family practice, the girl’s pediatrician immediately rushed her to the emergency room where she was prescribed antibiotics for an infection resulting from a spider bite. After her symptoms worsened, the girl was taken to UMass Memorial Hospital where an infectious disease specialist provided the girl with life-saving medical care once test results confirmed that a black widow had inflicted the bite. Academic field research has revealed that northern black widows are becoming more prevalent in the northeast and in Canada where global warming has made the temperate north more hospitable to the spiders. Researchers also believe that global warming likely played a part in the sudden arrival of large numbers of EEE infected mosquitoes in Massachusetts last year where 12 residents contracted the disease, three of whom ultimately died from EEE-related brain swelling.

Have you ever encountered a black widow spider in the northeast?