Cow Killer

The Cow Killer or Velvet Ant (Dasymutilla occidentalis) is a parasitic wasp that lays its eggs in the larvae of bumble bees. Cow Killer larvae destroy the immature bees as they grow. The scarlet color comes from velvet-like hairs on the insect. These red and black warning colors advertise a very unpleasant experience for any person or animal that bothers it. The name "Cow Killer" reportedly comes from the experience of a cow getting this insect trapped inside its hoof, getting stung repeatedly, and reacting with such violence (because the sting is very painful) that it broke it's leg and had to be put down. The Cow Killer's stinger is as long as its body and very thin and flexible.  

Note the stinger extended under the forceps.