Hornet

Vespa crabro

21-32mm (Worker)

28-39mm (Male & Queen)

Late May to October

Britain’s largest social wasp, the hornet is often feared due to its large size and loud droning buzz, but it is actually one of the most docile social wasps and even a fully active nest can be observed at very close range.

Queens emerge in mid to late spring, usually looking for a nest site after most other social insects. Occurring mainly in southern England and East Anglia, the preferred nest site is often a hollow tree in old woodland, but once established the workers will fly far from the nest in search of food. Emerging Queens may enter homes in search of suitable nest sites but can be easily let outside through a window. 

 Large Queen found searching for a nest site at the edge of a woodland clearing.

The first workers raised by the queen - seen around June - are much smaller than the workers and males produced later in the year. Males have longer antennae with 13 segments rather than the 12 of females. They are also stingless, much like other male wasps, and the abdomen has 7 segments rather than the female’s 6, ending in a blunter tip. 

 Male specimen

Another male showing darker variation in markings. 

Markings are chestnut-red and dull yellow, rather than the black and yellow of other social wasps, and the deeply notched eyes are brown. Wings are translucent orange-brown.

both sexes have a yellow head with very large powerful jaws for killing and macerating prey – including butterflies, wasps, grasshoppers, beetles, caterpillars and sometimes carrion. Adults will also feed at tree sap and over-ripe fruits such as fallen apples. The three ocelli on top of the head are surrounded by a small patch of brown or red (examples of Vespa crabro from outside of Britain will have a red or brown tone to the whole top and back of the head). 

Queen Vespa crabro comparison with other British social wasp Queens.

Male Vespa crabro comparison with other British social wasp males. 

Unlike most social wasps, hornets are active both day and night, and can be attracted to lights, sometimes showing up in moth traps.

The large mated queens over-winter in sheltered spots - sometimes garden sheds, or under logs.

The hover-fly Volucella inanis is often seen buzzing around hornet nests as its larvae live as scavengers within the hornet colony. 

Queen and worker Vespa crabro showing size difference. 

The head of the Queen is also usually bulkier than any workers. 

The large hover-fly Volucella zonaria (left) is an excellent mimic of Vespa crabro - especially in flight where the colouration and sound mimics the hornet exactly.

Hornets are far less likely to be attracted to human foods as other social wasps, and are often attracted to carrion where they carve small pieces of meat away to take back to the larvae in the nest.