European Hornet

Vespa Crabro

Appearance

The queen is 25 - 35mm long. The males and workers are smaller. The colour of the head and thorax is dark reddish brown and the abdomen is a deep yellow to orange striped with brown to black. Male antennae have 13 segments and the abdomen has 7 segments. Female antennae have 12 segments and the abdomen has 6 segments. Females also have an egg-laying tubular structure at the end of the abdomen called an ovipositor. European hornets have a large stinger as well as a large poison sac.

Lifecycle

Eggs develop into larva in 5 - 8 days. They will pass through five larval stages in the following 12 - 14 days. When fully grown, the larva metamorphose into young hornets during the next 13 - 15 days. Young hornets then emerge from their cells. Between mid August and mid September, the hornet colony achieves its developmental peak.

The appearance of the first sexuals (queens and males) indicates the decline of the colony. The old queen leaves the nest and dies. Workers now feed the sexuals with protein and carbohydrates needed for the long hibernation phase. With a short lifesspan (3-4 weeks), the last female workers die at the beginning of November.

Feeding Habits

A large hornet colony can feed up to a half Kilo of insects to its brood in one day. Flies represent approximately 90% of this. They dismember captured insects, removing head, legs, wings and abdomen. Only the thorax, with the flight muscules are fed the larvae. They will also feed on the sap from trees and shrubs and on the juice from ripe fruit. Damaged trees and shrubs are highly attractive to other foragers, such as flies, sometimes in great numbers. Hornets will forage for food both during the day and at night. Hornets are attracted to lights but are not attracted to human foods.

Nest

Nests are built in protected areas such as in hollow trees, balconies or attics. Mature nests consist of 6- 8 horizontal combs, up to 60-90cm length, 50cm in diameter and may contain 800-1000 workers. Hornet nests are not reused from one year to the next. A new nest is built in the spring.