#3
As Whitney described this species in 1879, I think we may assume he wasn't using "bimbo" in a 20th century way. Literally the species name means "black child" in Latin/Italian but why he used that term for a
Chrysops ...?
Of course, as a species it is best known for its funny name - a Google search using it will lead to many sites that specialise in funny species names - evidence that entomologists have an outstanding sense of humour!