Blackfly
Guides
Aphis fabae
black bean aphid, blackfly, bean aphid, beet leaf aphid
Aphis fabae is a small, soft-bodied aphid in the family Aphididae, commonly known as the black bean aphid or blackfly. It is a significant agricultural pest with a broad host range, attacking beans, sugar beet, and numerous other crops. The species exhibits a heteroecious life cycle with host alternation between a woody primary host (Euonymus europaeus, spindle tree) and herbaceous secondary hosts. It reproduces parthenogenetically during the growing season and sexually in autumn, producing overwintering eggs. The aphid is capable of rapid population increase through viviparous reproduction, and winged forms develop seasonally to facilitate migration between host plants.