Potato aphid (likely)

Common on tomato, potato, and other garden plants, especially on young shoots and the undersides of leaves in temperate regions.

Feeds by piercing plant tissue and sucking phloem sap. Heavy infestations cause curling, yellowing, stunted growth, and sticky honeydew buildup.

Often forms dense colonies, reproducing rapidly by live birth during the growing season; winged individuals disperse when plants become crowded or stressed. Ants may tend colonies for honeydew.

Can transmit plant viruses and promote sooty mold, reducing crop vigor. It is also food for lady beetles, lacewings, hoverfly larvae, and parasitoid wasps.