What is "bean aphid"

black fly \black fly\, blackfly \blackfly\, (Zo["o]l.)

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.

2. A black plant louse, as the bean aphis ( Aphis fab[ae]), which infests e. g. beans and sugar beets; -- called also bean aphid.

n. blackish aphid that infests e.g. beans and sugar beets [syn: blackfly, Aphis fabae]