Common wasp

Grown-up wasps like sweet food, like flower nectar.

They catch small insects to feed to the baby wasps.

Adult wasps mostly drink nectar and look for other sugary food, such as honeydew, a sweet liquid made by tiny insects. That sweet tooth is why wasps sometimes visit picnics with jam or fizzy drinks in late summer.

The young wasps, called larvae, need protein to grow. So the workers hunt aphids, caterpillars, flies and spiders and bring them back to the nest. This makes wasps important insect-controlling predators.

Buglife reports that adults feed predominantly on nectar and other sugars, such as honeydew and human foods, while larvae are fed protein from prey including aphids, caterpillars, flies and spiders. Workers gather protein for the larvae and sugar for themselves, which explains their late-summer interest in sweet foods.

Where it is invasive, this diet has large effects. New Zealand's Department of Conservation reports that in some beech forests wasps consume massive amounts of honeydew produced by a native scale insect, a food also important to native birds, bats, insects and lizards, and that they eat huge numbers of native insects.

Wasps make paper!

They chew wood and mix it with spit. Then they build a round nest with lots of little rooms.

Common wasps are amazing builders. A worker scrapes tiny bits of wood, chews them and mixes them with saliva to make a kind of paper. With this paper, the wasps build six-sided cells for the young and wrap them in a round outer shell.

They build nests in sheltered places such as old animal burrows, cracks in walls and holes in trees. A wasp may sting if it is defending its nest, so it is best to leave nests alone and let an adult deal with any problem.

Buglife describes nests built from chewed-up wood and saliva, forming a paper-like material shaped into hexagonal cells within a spherical nest, sited in deserted mammal holes, cracks in walls or holes in trees. New Zealand's Department of Conservation notes that common wasp nests are brown, while German wasp nests are gray.

Workers forage for prey and sugars and defend the nest; Buglife notes that wasps may sting in defense of the nest. Large late-summer colonies with many adults and few larvae explain why wasps are most noticeable in September.

In Europe, wasps help gardens by eating pest insects.

In New Zealand, wasps are not from there. They take food that other animals need.

In its home range, the common wasp is doing fine: Buglife says its population in the UK is stable. Wasps help gardens by eating insects such as aphids and caterpillars.

Far from home, it is a different story. In New Zealand, introduced wasps eat many native insects and take sweet honeydew that native birds, bats and lizards need. Conservation workers there use a special bait to control them.

There is no IUCN Red List assessment of the species' conservation status. Buglife lists the UK population trend as stable, with habitat loss and loss of food for larvae as threats, and stresses the wasp's value as a predator of other insects.

As an invasive species it is serious: Rendoll Cárcamo and colleagues note that it is on the IUCN list of 100 of the world's worst invasive alien species (Lowe et al. 2004). New Zealand's Department of Conservation reports harm to native birds and insects and disruption of beech-forest food chains, and uses Vespex, a protein bait that workers carry back to the nest, to control wasps over large areas.