What is "carrot fly"

Negro \Ne"gro\, a. Of or pertaining to negroes; black.

Negro bug (Zo["o]l.), a minute black bug common on the raspberry and blackberry. It produces a very disagreeable flavor.

negro corn, the Indian millet or durra; -- so called in the West Indies. See Durra.
--McElrath.

Negro fly (Zo["o]l.), a black dipterous fly ( Psila ros[ae]) which, in the larval state, is injurious to carrots; -- called also carrot fly.

Negro head (Com.), Cavendish tobacco. [Cant]
--McElrath.

Negro monkey (Zo["o]l.), the moor monkey.

The carrot fly (Chamaepsila rosae) is a pest of gardens and farms, and mainly affects the crop of carrots, but can also attack parsnips, parsley and celery. It is a member of the family Psilidae (order Diptera).