Field Guide to Venomous and Medically Important Invertebrates ...

one South American species, Lycosa raptoria, have been shown to produce necrotic lesions, and
victims may experience swollen lymph vessels around the bite area with eventual eschar
formation and sloughing of the wound.
Figure 28. Garden spider (Argiope sp.), North America. Photo: Jeff Barnes.
Figure 29. Jumping spider (Phidippus sp.), Thailand. Photo: John Moore.
Figure 30. Wolf spider (Lycosa avida). Source uknown.
Other spiders from different regions of the world may also produce mild arachnidism, but such
cases are seldom reported and are not generally considered medically significant. Treatment for
these milder cases of necrosis should include immobilization and elevation of the bitten area,
cold compresses, analgesics, tetanus boosters, and systemic antibiotics for secondary
infections.
Tarantulas
Though widely feared, tarantulas (Family Theraphosidae) are not particularly dangerous to
people. Bites from their long, needle-like fangs, can be quite painful, and the setae shed from
their bodies can be a painful urticarial irritant when introduced into the eyes or mucous
membranes. However, their venom produces a reaction comparable in physical character to that
of bees and wasps. Localized reactions for a tarantula bite can be treated with topical
corticosteroids, systemic antihistamines, and cold compresses.
Figure 31. Tarantula. Photo: David Bowles & Mark Pomerinke.
Scorpions