'blackfly' definitions:

Definition of 'blackfly'

(from WordNet)
noun
Blackish aphid that infests e.g. beans and sugar beets [syn: blackfly, bean aphid, Aphis fabae]
noun
Small blackish stout-bodied biting fly having aquatic larvae; sucks the blood of birds as well as humans and other mammals [syn: blackfly, black fly, buffalo gnat]

Definition of 'blackfly'

From: GCIDE
  • black fly \black fly\, blackfly \blackfly\, (Zool.)
  • 1. In the United States, a small, venomous, two-winged fly of the genus Simulium of several species, exceedingly abundant and troublesome in the northern forests; -- called also buffalo gnat. The larv[ae] are aquatic. It sucks the blood of birds as well as humans and other mammals. [WordNet 1.5 + WordNet 1.5]
  • 2. A black plant louse, as the bean aphis (Aphis fab[ae]), which infests e. g. beans and sugar beets; -- called also bean aphid. [WordNet 1.5]