Anything is possible, but here's the rationale the doctors who were treating me used to reach their conclusion: In Virginia there are only two known population

Anything is possible, but here's the rationale the doctors who were treating me used to reach their conclusion: In Virginia there are only two known populations of venomous spiders, the black widow and the brown recluse. A black widow bite was ruled out because I did not exhibit any of the "typical" symptoms that they'd had experience with. I didn't have any pain outside of the bit marks (until later when my lymphatic system started to show signs of blood poisoning and an ache set in). From what I understand black widow bites start off as a "bee sting" type pain and then progress to abdominal pain and full-body muscle spasms. But as you alluded to, without a specimen, it was an educated guess on their part based on my memory of where I'd been during the week prior to the bite.