Giant Willow Aphid

Found on various species of willow (Salix) and occasionally poplars; often seen on trunks and branches rather than leaves.

Strictly herbivorous, feeding on the phloem sap of willow trees.

They often aggregate in large, dense colonies. They are known for a peculiar defense behavior where they kick their hind legs in unison when a predator approaches. They reproduce parthenogenetically (without mating) and give birth to live young.

They do not bite or pose a direct health risk to humans. However, they extract large amounts of sap and excrete a sticky substance called honeydew, which can attract wasps and promote the growth of black sooty mold on nearby surfaces or automobiles.