Background information Edit
Dopterians were only identified by name in dialogue in the episode "The Forsaken". In the scripted stage directions for that episode, the Dopterian who robs Lwaxana Troi was described as a "small, weasely [sic] looking Dopterian who looks like a distant cousin to a Ferengi." (Star Trek: Deep Space Nine Companion - A Series Guide and Script Library)
Dopterians also shared an unusual resemblance to the Kobheerian species; their appearance was almost identical, but Dopterians had Ferengi-like noses, whereas Kobheerians had two large, elongated flat nostrils in the place of a nose.
According to Star Trek: Star Charts ("United Federation of Planets I") and Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), there was a star system named Dopteria (Kappa Coronae Borealis), which might possibly be the system of origin for this species, in the Alpha Quadrant. This was a a binary system of two K-class stars.