Black bean aphid (likely)

Colonies occur on the undersides and stems of broad-leaved plants, especially beans, beet, spinach, weeds, and some ornamentals. They are common in gardens, fields, and disturbed habitats.

They pierce plant tissues with sucking mouthparts and consume phloem sap. Feeding can cause curling, yellowing, stunting, and sticky honeydew deposits.

These aphids cluster in dense colonies, reproduce rapidly by live birth during favorable seasons, and may produce winged adults when crowded or plants deteriorate. They are often attended and protected by ants attracted to honeydew.

They can weaken crops and transmit several plant viruses, though identification from the image is not definitive. They provide food for lady beetles, lacewings, hoverfly larvae, and parasitic wasps.