Aphis fabae

black fly lack fly, blackfly lackfly, (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. [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]