Since this topic was off topic in another thread, I decided to give everyone a new place to express their thoughts on the matter.
I never forgot what Adrian Wenner shared about this topic many years ago. He said:
". . . may I quote from an opening statement in a book I published in 1971 (THE BEE LANGUAGE CONTROVERSY: AN EXPERIENCE IN SCIENCE): "My spelling of 'honey bee' follows the tradition in entomology." That is, if an insect really is what we know it to be, we use two words (e.g., honey bee, hover fly, bot fly, rove beetle) By contrast, if an insect falls outside what we consider common sense (e.g., butterfly, dragonfly), we reflect that situation by using only one word (a dragonfly is neither a dragon nor a real fly!).
Unfortunately, standard dictionaries follow no such tradition, causing those of who are authors much grief!
Someday I hope those who write dictionaries straighten out their act!"