rubytail

from The Century Dictionary.

• noun A gold wasp or cuckoofly of the hymenopterous family Chrysididæ, as Chrysis ignita, having the abdomen of a ruby color.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Zoöl.) A European gold wasp (Chrysis ignita) which has the under side of the abdomen bright red, and the other parts deep bluish green with a metallic luster. The larva is parasitic in the nests of other wasps and of bees.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun zoology A European wasp, Chrysis ignita, with a bright red underside of the abdomen.