Asian Giant Hornet

The Asian giant hornet is the largest known hornet species, a member of the social wasp family Vespidae found across East and South Asia. Queens can exceed 5 cm in length, dwarfing most other wasps, and colonies build underground or in low tree-cavity nests rather than the exposed paper nests of some other hornet species.

The species drew international attention after isolated detections in North America in the late 2010s, where local and state agencies undertook nest-eradication efforts; established populations were subsequently eliminated from the areas where they were found. In its native range it is a well-known, long-studied insect, notable for its size, its distinctive group-hunting behavior against honey bee colonies, and its role as a top invertebrate predator in its ecosystem.

Ecologically, Asian giant hornets are important predators of large insects and, in group "slaughter phase" raids, can rapidly kill and decapitate the workers of a honey bee colony to seize the brood as food for their own larvae, a behavior that has made them a significant concern for beekeepers where the species occurs.

• Very large wasp, 35–50 mm long, with a broad, orange, drop-shaped head, large eyes, and strong mandibles.
• Thorax dark brown to black; abdomen banded in alternating bright orange-yellow and dark brown stripes.
• Wings are smoky brown and held flat over the body at rest; legs are long and orange-brown.
• Distinguished from smaller hornets and yellowjackets chiefly by its exceptional size and unusually large, rounded orange head.

Native to forested lowlands and mountains across Japan, Korea, China, Taiwan, and other parts of East and South Asia, the Asian giant hornet nests underground in abandoned rodent burrows or in cavities at the base of trees, rarely in fully exposed locations. Adults are active from spring through autumn, with colony activity, including honey bee raids, peaking in late summer and early autumn as colonies grow and require more food for developing brood.

Asian giant hornets are social insects living in colonies founded by a single queen each spring, with workers foraging for other insects, tree sap, and fruit to feed the colony. Their most distinctive behavior is coordinated raiding of honey bee colonies in late summer, when small groups of hornets can overwhelm and kill large numbers of bees to carry off larvae and pupae as protein for their own brood. They communicate hunting sites via pheromone marking and are capable of sustained, fast flight when foraging or defending the nest.

Colonies follow an annual cycle typical of social vespid wasps: a mated, overwintered queen emerges in spring to found a small nest and raise the first brood of workers alone, after which workers take over foraging and nest-building while the queen focuses on egg-laying. The colony grows through summer, producing new queens and males in late summer and autumn, which disperse to mate. Only newly mated queens survive the winter, hibernating in sheltered ground sites before founding new colonies the following spring; the old colony, including the founding queen, dies off with the onset of cold weather.