What is the name of a stinging insect?

Insects do not have 'tails'. Some have specialised structures at the end of their abdomens called ovipositors, used for laying eggs. Some species have specialised this organ even further, into stingers. Wasps, bees, hornets, and some ants, have these stinging organs.

If you are referring to a Scorpion, this is an arachnid, not an insect.