German Wasp

• biologíaIt lives in annual colonies that die out almost entirely over winter; only the newly mated queens survive to found fresh colonies in spring.
• It builds its nest by chewing wood and mixing it with saliva: it is genuine paper, and the technique is often cited as the natural forerunner of human papermaking.
• For most of the summer it hunts insects to feed the larvae, and it is the larvae that give the workers a sugary droplet in return; when the brood runs out in August, the workers lose that reward, and that is when they invade café terraces in search of anything sweet.
• Introduced into New Zealand, Australia, Chile and Argentina, it forms colonies there that survive several winters and reach sizes impossible in Europe.
• It reached New Zealand around 1945, probably with queens hibernating inside crates of aircraft parts brought from Europe after the war, and today that country has the highest densities of social wasps in the world.
• In New Zealand's beech forests there is an average of twelve nests per hectare, some 10,000 wasps, and up to 60 nests per hectare have been recorded.
• In those forests the biomass of social wasps exceeds that of all the native birds put together, and they prey on the native invertebrates.
• The colony is annual: it dies in autumn and only the mated queens survive, hibernating through the winter.
• The workers divide the labour by age: the young ones tend the nest and the older ones go out to forage.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Woodland, farmland and urban areas; it nests underground in excavated cavities, and in towns also in walls, lofts and building voids

Sexual maturity

The overwintering queens look for a nest site from mid-March, the workers are present from early May to mid-November, and the new queens leave the nest in September and October; the males fly from mid-August to mid-November

Gestation / incubation

The eggs hatch after 5-8 days; the larva moults five times over about 15 days, spins a silk cap over the cell and pupates for a further 8 to 18 days

Litter / clutch size

The queen lays a single egg per cell; the initial nest runs to about 25 cells and at its summer peak houses 2,000 to 5,000 wasps, with nests reaching 1.8 m across. Each cell is reused twice on average

Sources consulted: https://es.wikipedia.org/wiki/Vespula_germanica; Bumblebee.org, guia de avispas sociales; fichas de manejo de Vespula germanica; Manaaki Whenua Landcare Research (Nueva Zelanda), ciclo de las avispas Vespula; iNaturalist, ficha Vespula germanica; BWARS; BWARS, ficha Vespula germanica; BWARS, ficha Vespula germanica (Edwards 1980)

Best time: Peaks in late summer, when the workers switch to looking for sugars and come close to terraces and fruit; in October and November the last workers and the males feed on ivy flowers