Social Wasps, 1, 2, 3, 4

Social wasp fast facts

  • Queens and females have stings, but males do not
  • Adults feed on sweet liquids
  • Larvae feed on insects caught and cut up for them by the workers (their sisters)
  • Hornets are the rarest of the British social wasps, and easily recognised as they are yellow and brown in colour, and larger than the common German wasp
  • In Europe the hornets have a yellow head unlike the orange head of the British hornets
  • In temperate climates social wasps do not swarm.

Social wasps overview

The social wasps are in the Vespidae family. there are 4000 species world wide, and eight species in Britain. Their life cycle is similar to Bumblebees, in that it is annual, with only the newly mated queens surviving the winter by hibernating (see for recent changes in Hawaii and New Zealand). Wasp queens do not hibernate underground as bumblebees do, but usually choose a dry, cool, sheltered spot. I regularly find queens hanging on by their jaws to the underside of logs in my wood pile. Adults range in size from 10 - 30 mm long.

Social wasps in Britain

Dolichovespula media
Body lengths in mm Queen 18 - 22, Worker 15 - 19, Male 15 - 19.
Flies Jun - Oct
Found in England, Wales, southern Scotland. Arrived in the U. K. in the 1980s. Nests in trees and occasionally on the outsides of buildings. The workers of this species will vigorously defend the nest.

Dolichovespula norwegica, Norwegian wasp
Q 15 - 18, W 11 - 14, M 13 - 15
Flies Apr - Sept
Found in woodlands. Nest in trees, under eaves and on walls, usually not too high up, near heaths and moors. More common in Scotland and the north of England, scarcer further south. Also found in northern Europe and Asia. Colony size is quite small with a few hundred workers at peak. Populations have been declining from the 1990s. Queens fly from mid April, workers from July, and new queens and males from September.

Dolichovespula sylvestris Tree wasp
Queens up to 18 mm, workers up to 16 mm.
Flies May to September
Found throughout U. K., also in Europe, Morocco, across central Asia into China, often nests in gardens, in tree holes, bird boxes and roof spaces. Colony size is small. Queens fly from early May, workers from June, and new queens and males from July.
Intriguing research has found that this wasp is getting smaller. Research in Spain using museum specimens that date back to 1904 has found a decrease in wing size. This decline in size correlates with a rise in temperature. Temperature increase has been shown to lead to a decrease in size of vertebrates, e. g. antelope and sparrows. The team that produced the results are unsure if climate change is the cause, but it is known that an higher temperature does speed up grub development in wasps. This speedy development leads to earlier emergence as adults and a smaller average adult size. These results have implications for many other holometabolous insects. Many museums hold collections that could be used in such studies.
Dolichovespula saxonica, Saxon wasp
First seen in the U. K. in 1987, and the first nest in East Sussex in 1991. Closely related to the Norwegian wasp, but more commonly found in urban locations. Colony size is small. Nests in bushes, under house eaves, in garages and barns, and cavity walls. The nest can be invaded by the wax moth, Aphomia sociella, which will destroy the nest.
Vespa crabro, the hornet
Q 23 - 25, W 18 - 15, M 21 - 28
Flies May - Aug
Head, thorax and abdomen with orange/brown instead of yellow/brown
Vespula germanica, German wasp
Q 17 - 20, W 12 - 16, M 13 - 17
Flies March - Sep
3 small black spots between eyes. Nest in cavities and holes in the ground. Nest size can reach a diameter of 1.8 m and contain thousands of individuals.
Vespula vulgaris, the common wasp
Q 16 - 19, W 11 - 15, M 13 - 17
Flies Apr - Sep
Anchor-shaped mark between eyes. Nests in cavities, holes in ground, attics, out houses, bushes, almost anywhere. Nest can be as large as 2.25 m in diameter, and can be active as late as November in the south of England.
Vespula rufa, red wasp
Q 16 - 20, W 10 - 14, M 13 - 16
Flies Apr - Sep. Found throughout Britain. Prefers open locations in woods, moors and hedge banks. Colonies can now survive until November in favourable conditions.
2 abdominal segments nearest abdomen have orange/red patches. Prefers drier soil types. Nests at ground level or underground, in grassy tussocks, tree stumps and out houses. A successful colony can rear around 450 workers, 180 males, and 200 queens.
Vespula austriaca
Females 19 mm
This is a cuckoo wasp on Vespula rufa. The female invades V. rufa's nest when there are just a few workers. She kills the queen and lays her own eggs leaving V. rufa's workers to rear them. Found only where V. rufa is found.

Wasp food and eating habits

Wasp grubs (see the drawing below) are carnivorous, the adults bring them prey which is mainly other insects. This is chewed up into a paste by the workers and queen and fed to the grubs. An adult wasp can fly with prey that weighs 4/5 of her own body weight back to the nest. As many of these prey items are regarded as "pests" by gardeners, it is clear that the wasp should be regarded as the gardener's friend.

Vespula vulgaris, the common wasp showing the spiracles

Adult wasps prefer sweet foods such as nectar, jam, ice cream, and as the adults feed the grubs the grubs exude a sweet liquid which the adult wasps lap up. Towards the end of summer when the queen has stopped laying eggs and all the grubs have hatched into adults, there is no more need for the adult wasps to bring back insect prey, and no grubs to give the adults the sweet substances they crave. So the adults go out and search for sweet substances. They find sweet nectar in flowers, but as they have short tongues they cannot reach the nectaries of some flowers. It is at this time of year that wasps become a nuisance to man if they discover our sweet foods such as sugar, jam, ice cream, etc. In northern Europe wasps do not store food in their nests.

Wasp larvae

The larvae (above) are carnivorous eating chewed up bits of insects fed to them by adult wasps. In return the grubs exude a sweet secretion in their saliva which is lapped up by the adult wasps. The grub moults three times, and tightly fits its cell after the last moult.

The wasp queen

Vespula vulgaris queen, common wasp queen

The Vespula vulgaris queen above and below is 16 - 19 mm long. The nest is started by the queen, and is about the size of a walnut and contains 10 - 12 hexagonal cells. The queen then lays an egg in each cell. The cells point downwards, but the egg is partially stuck to the side, so it does not fall out. On average each cell is used twice.

Vespula vulgaris, common wasp showing the 3 ocelli or primitive eyes

Above you can see a close up of a queen's head showing the 3 simple eyes or ocelli.

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