Black aphid (likely)

Plant stems, leaves, buds, and undersides of foliage, especially on tender new growth. They may also occur indoors on houseplants.

They pierce plant tissue and suck phloem sap. Feeding can cause curling, yellowing, wilting, sticky honeydew, and sooty mold.

Often occur in dense colonies and reproduce rapidly, frequently by live birth; winged forms develop when plants are crowded or stressed. Ants may tend them for honeydew, while lady beetles, lacewings, and parasitoid wasps prey on them.

Generally harmless to people and pets, though heavy infestations can weaken plants and some species transmit plant viruses. They provide food for beneficial predators and contribute honeydew to insect communities.