Black bean aphid

Editorial diagnosis

Diagnosis overview

Black bean aphid forms dark colonies on beans, chard, and other crops.

In gardens, Black bean aphid can occur on plants including broad bean, Runner bean, Common bean, Swiss Chard. In the available profiles, it is linked mainly with Leafy vegetables, Legumes.

Its importance depends on how quickly it spreads and whether seedlings, shoot tips, flowers, or fruit are affected. Remove heavily infested shoot tips and support beneficials.

Inspect leaf undersides, shoot tips, and the soil around the plant at different times of day. Eggs, larvae, droppings, webbing, or slime trails are often more diagnostic than one damaged leaf.

A common mistake is to treat feeding damage without checking the animal, eggs, larvae, time of activity, and affected plant parts.