Paper wasps are beneficial insects that are a natural part of the native ecosystem and play an important role in pollination and pest population control.
Paper Wasp Identification
There are many species of paper wasps worldwide, so they do vary in appearance, but the distinctive grey papery inverted-cone nest that they all build and inhabit makes them very easy to distinguish from other type of wasps.
The common Australian paper wasp (Polistes humilis) has a slender reddish-brown body around 10–15mm in length with a very narrow waist, a small head with medium sized eyes, medium length antennae and distinct yellow face. The abdomen (lower body section) and thorax (upper body section) has black sections with yellow/orange bands. There are two pairs of brown tinted wings, with the front pair of wings (forewings) larger than the rear hindwings.
Paper Wasp Nest Building
Paper wasps are social insects that live in colonies, much like bees. A new nest is built each season by a single female, who becomes the queen for the colony. Sometimes more than one female will start a new colony together, and in such cases only one female becomes the queen and the rest become workers.
A young female paper wasp who will become a queen builds her inverted cone-shaped nest by using her strong mandibles (jaws) to scrape and chew wood fibres, mixing them with saliva to make a pasty pulp which becomes quite paper-like when it dries.
The queen lays an egg into the underside of each hexagonal papery cell of the comb, which hatches and develops into a grub-like wasp larva. Paper wasps catch lots of caterpillars and other small insects to feed the larvae, but the adult paper wasps mainly feed on nectar, just like bees, making them important pollinators in the garden.
Once the larvae mature, they pupate in their cells and emerge as adult wasps that join the colony. The first brood that hatches will become workers that will take over the task of building the nest for the queen.
As more offspring develop and the colony size increases, the new wasps take over the major duties of collecting food and taking care of the young, as well as maintaining and defending the nest.
Paper wasps form small colonies or around 20-30 adults and construct their grey paper nests in high positions in protected locations, usually with some type of overhand, such as beneath tree branches, in shrubs, on rock faces, under the eaves of houses (roof overhangs) and open porch ceilings.
Are Paper Wasps Dangerous?
When they’re left undisturbed, paper wasps can keep garden pests at bay, and these beneficial insects form small colonies that are not as aggressive as European wasps, they’ll only attack humans if their nest is disturbed, but they can deliver painful stings!
It’s fascinating to observe paper wasps (from a safe distance) while they build their nests fibre by fibre to create their grand looking nest! Since paper wasp colonies disband after a season, it’s best to just let them be for the year they are there, to do their work controlling pests, after which they will disperse and move elsewhere.
Paper Wasps vs European Wasps
Paper wasps are sometimes mistaken for European wasps, but they have certain distinguishing characteristics.
Paper wasps have yellow-orange antennae, longer, more slender bodies, they fly with their legs dangling. They aren’t attracted to meat, and only build exposed, above-ground nests.
European wasps (Vespula germanica) are also known as German yellowjackets in the US. They are pests that are harmful to the environment and a danger to people. We can identify European wasps by the following characteristics:
- Smooth, shiny, stout bodies, workers 13 mm long, queens 18 mm in length.
- Bright black and yellow bands, with arrow-shaped black markings on the black bands running down the centre of the abdomen, and pairs of small black spots on the yellow bands.
- Long, clear transparent wings.
- Black antennae, legs mostly yellow, flying with their legs held close to the body.
- Nests are usually hidden underground in in a cavity, such as a wall cavity or roof space.
European wasps also construct papery nests made out of chewed up wood fibres, but they almost never build them out in the open, unless there’s competition for nesting cavities by other European wasp colonies.
Note: Wasp nests are made of mud belong to another type of wasp, and not to European wasps.
The tendency of European wasps to build their nest in close proximity to human habitation makes them a potential danger. Their colonies are very large, often numbering in the thousands, and they have a reputation for being very aggressive and notoriously defensive of their nests. They will chase away animals, and often follow them for long distances!
Unlike most wasps which are quite clean, European wasps are a health hazard. To source protein to feed their developing larvae, they scavenge meat from dead animals and garbage bins, as well as from pet food and picnic tables, and live nestling birds which they kill, in addition to the usual spiders and insects.
To keep nature in balance, don’t disturb paper wasps, but definitely control European wasps with traps, as they’re a real menace!
References
- Clemson University Cooperative Extension Service, Paper Wasps <https://www.clemson.edu/extension/beekeepers/fact-sheets-publications/paper-wasps.html>
- N.C. (North Carolina) Cooperative Extension, Paper Wasp Swarming Around Structures Entomology Insect Notes <https://content.ces.ncsu.edu/paper-wasp-swarming-around-structures>
- NSW Government Department of Industry, Australian paper wasps <https://www.dpi.nsw.gov.au/biosecurity/plant/bees-and-wasps/australian-paper-wasps>
- Australian Museum, Paper Wasps, Updated 28/02/22 <https://australian.museum/learn/animals/insects/paper-wasps/>
