from
The Collaborative International Dictionary of English v.0.48
Sphex \Sphex\, n.[NL., fr. Gr. ???, ???, a wasp.] (Zool.)
Any one of numerous species of sand wasps of the genus
{Sphex} and allied genera. These wasps have the abdomen
attached to the thorax by a slender pedicel. See Illust. of
{Sand wasp}, under {Sand}.
[1913 Webster]
{Sphex fly} (Zool.), any one of numerous species of small
dipterous flies of the genus {Conops} and allied genera.
The form of the body is similar to that of a sphex.
[1913 Webster]