Some useful information on insect/arachnid bites

Characteristic pustules from fire ant bites.
(see larger image for details)

Characteristic tick bite (from Wisconsin) of Lyme Disease

Differentiating inflammation/necrosis from Lyme Disease tick bite or from brown recluse spider bite.

More info

Necrosis on dog leg and human leg attributed to brown recluse spider bites. Another human leg bite.