Yellow Hornet (Vespa simillima) — identification, habitat & look-alikes

The yellow hornet is a common East Asian hornet known for building the biggest hornet nests in Japan, often under the eaves of houses. It lives in Japan, Korea, China, and the Russian Far East and isn't found in the US. Mainland populations are darker and hairier than the bright yellow form that dominates most of Japan.

Appearance

Appearance: Queens are about 1 in (25–28 mm) long and workers 0.7–0.9 in (18–24 mm), small for a hornet. The brighter Japanese form has a yellow head, black thorax, and a brown-and-yellow striped abdomen, all covered in yellowish hair; the mainland form has less yellow.

Look-alikes

European hornetVespa crabro

The European hornet, the hornet most Americans actually see, has wavy yellow-and-black bands on its abdomen and often flies after dark.

Why they get mixed upBoth are yellow-and-dark hornets that nest in cavities and around buildings.

Where it lives

Typical habitats: Towns and cities
Woodland edges
Range: Japan, the Korean Peninsula, China, Sakhalin, and eastern Siberia. Not found in North America.
Preferred conditions: Very flexible about nest sites: tree hollows, underground cavities, rock walls, and bushes in the wild, and attics, eaves, wall voids, and vents around houses.

Behavior

Diet: Adults drink tree sap, nectar, and fruit juice, and will even visit discarded candy. Workers hunt insects and spiders for the larvae; more than 40 prey species have been recorded.
Social life: A single queen starts each colony alone. Colonies often begin in an enclosed spot and may move to a bigger, open site partway through the season.

Life cycle

Nest: A nest usually lasts about seven months. In Japan, large nests often hold around 6,000–8,000 cells, and some top 10,000.

Cautions

Cautions: Very defensive near its nest and may attack in groups. In Japan it is regarded as a leading cause of hornet stings, mostly in fall.

Name and classification

About the name: The bright yellow form of most of Japan was named Vespa simillima xanthoptera, and the darker mainland form V. s. simillima. A recent revision treats all hornet subspecies names as synonyms, so these are now best thought of as regional color forms.