Assassin Bug Nymph
5862 This bug was inside my step son shirt in the arm pit and bit him. The bite left a welt like a bee sting and he said it felt like 2 bees stinging him. Eastern Washington.
This is a nymph of an assassin bug (Hemiptera/Heteroptera: Reduviidae), likely that of Reduvius personatus, a peridomestic species known as the masked hunter. These are reported as having a very painful but not dangerous bite. See http://tinyurl.com/23g4bdy for more detailed information. Saugstad, retired entomologist; Sinks Grove, WV.