the hover-fly

Any fly of the insect family Stratiomyidae, which resemble wasps.

Any insect, of the order Trichoptera, having two pairs of hairy wings; they are found near lakes and streams

any insect of the Tephritidae family, whose larvae damage plant tissue.

any fly of the family Sarcophagidae that feed on carrion

(idiomatic) Something (especially a minor thing) which ruins or spoils everything else, or makes it less pleasant; a nuisance or problem; a disagreeable or unpleasant detail.

Alternative spelling of botfly

(idiomatic) A quiet, non-participating, or unseen observer; an eavesdropper or witness.

A poster, especially for advertisement purposes, put up illegally / One who posts such posters

present participle of fly-pitch