|Description:||Under a magnification of 41X, this scanning electron microscopic (SEM) image revealed some of the ultrastructural architecture found in a brown recluse spider’s, Loxesceles reclusa, web that had entrapped an unidentified ant. Note the silken threads used to enwrap this prey, and the gluey matrix in which the threads were embedded, much like rebar and concrete.|
Although spider bites are common in many parts of the United States, most domestic spiders are not substantially venomous to man. The best known exceptions are widow spiders, i.e., Latrodectus spp., including the black widow L. mactans, and brown spiders Loxesceles spp., particularly the brown recluse, Lox. reclusa. However, cases of arachnid envenomation from the hobo spider, Tegenaria agrestis, are being reported increasingly in the Pacific Northwest.
Sometimes a bite from a brown recluse spider can go unnoticed, or maybe feel as slight as a pinprick. However, usually, after 2–8hrs, there is ensuing severe pain, erythema, and localized tissue necrosis due to the venom’s proteolytic enzymes. See PHIL 6265, and 6266 for images showing the after affects of a L. reclusa bite.