Paper wasps
Yes, with a caution. Paper wasps (Polistes) are slender wasps, 1/2–1 in long, that hang open, umbrella-shaped paper nests under eaves and branches. The adults drink nectar, but they hunt caterpillars to feed their young. Colonies placed in tobacco fields cut hornworm numbers by 60%, and in a 2024 Iowa hoop-house trial they cleared caterpillars from broccoli. They are much less defensive than yellowjackets and rarely sting away from the nest. They will defend the nest, though, and a sting can cause a life-threatening reaction in an allergic person. UC IPM's rule is simple: a paper wasp nest does not need treatment unless it is near people.
At a glance
- Kind
- Wild — attracted, not bought; stings
- Adult
- 1/2–1 in; slender waist, legs dangle in flight
- Nest
- One open comb on a stalk; rarely bigger than a hand
- Colony
- About 10–200 wasps at peak; usually lasts one season
- Feeds young on
- Caterpillars, chewed into a ball
- Forages
- Up to about 1,000 ft (300 m) from the nest
How it works
Each nest is started in spring, usually in April in Missouri, by one or a few queens that spent the winter in a sheltered spot. They build a single comb of downward-facing cells from chewed wood fibre and saliva, hung by one stalk. There is no outer paper envelope, so the cells, and sometimes the white larvae, can be seen from below. Workers raised through the summer do the hunting. Males and new queens appear in mid to late summer, and in autumn every wasp dies except the mated queens. Nests are very rarely reused.
A foraging wasp hunts alone, often returning to places where it has found prey before. It kills a caterpillar, chews it into a tight ball and carries it back to share with the larvae; the adults themselves live on nectar and fruit juice. The evidence that this protects crops is real but limited. Nests moved into tobacco fields cut hornworm numbers by 60% and crop damage by 74% (Lawson et al. 1961). In a 2024 Iowa State hoop-house trial, P. metricus removed every cabbage looper, cabbageworm and diamondback moth caterpillar placed on broccoli and reduced leaf damage. With P. fuscatus on kale, by the second day wasps took over 80% of the looper larvae within three hours of their being put out.
Polistes are not used in any large-scale biocontrol, partly for lack of research and partly because people dislike wasps. Missouri's field guide counts about 24 species north of Mexico; UF/IFAS gives 17 for North America. The introduced European paper wasp (P. dominula) is particularly abundant in towns, and it is a mixed blessing: in Kentucky pollinator gardens it killed most of the second- to fourth-instar monarch caterpillars it met on milkweed.
What it is confused with
Paper wasps get blamed for yellowjackets, which UC IPM calls by far the most troublesome social wasps. The nest and the waist tell them apart.
- PestYellowjackets — Jagged bright yellow-and-black bands and a barely visible waist. They nest in the ground, in wall voids or in grey paper balls with a single entrance hole, defend the nest hard, and scavenge at picnics and bins. Paper wasps have a long, slender waist, an open comb, and rarely come to food.
- Also goodMud daubers — Dark, thread-waisted solitary wasps that build small, hard mud nests on walls and ceilings. UC IPM says they do not defend them and rarely sting; the nests can be scraped off in winter.
- Also goodHoney bees — Hairier and less brightly striped. They nest in cavities in trees or houses rather than open combs, and are unlikely to sting unless trapped or stepped on.
- PestBald-faced hornets — Aerial-nesting yellowjackets, marked with white rather than yellow, that build enclosed grey paper nests with a single entrance hole at the bottom, on eaves or tree limbs. UC IPM calls aerial yellowjackets extremely defensive; treat their nests with far more caution than a paper wasp's.
How to keep it around
Paper wasps come on their own; the choice is where to let them nest. Tolerate a nest when it is away from doors, paths, play areas and fruit you pick, and nobody in the house is allergic to stings:
- Leave nests under eaves, in sheds or in shrubs away from traffic; UC IPM says social wasps should be protected and encouraged to nest where people and animals seldom go
- Remove a new nest early instead of spraying a big one later: knocking down a spring nest with a broom usually sends the lone queen to start again elsewhere
- If a nest by a door must go, UF/IFAS advises doing it in the evening, when the wasps are inactive, with a labelled wasp and hornet spray; UC IPM says calling a professional is easiest and safest
- Flowering plants nearby: the adults drink nectar
- Simple wooden nest boxes, which researchers use to draw Polistes to nest near crops
- Do not swat foragers on plants: away from the nest they are usually not aggressive
Pesticide sensitivity
Nest sprays are the main threat, and they are also a stinging risk to whoever applies them: UC IPM warns that wasps attack when they sense a poison being applied to their nest. Paper wasp nests rarely need them. Open the compatibility matrix →
When to choose something else
A paper wasp nest is a bonus, not a plan. Look elsewhere when:
- Someone in the household is allergic to stings — remove nests near the house early in the season, while they are small and have a single queen
- Wasps are scavenging at food and bins in late summer — those are yellowjackets; UC IPM covers traps and nest treatment
- Caterpillars are stripping a crop now — use Bacillus thuringiensis (Bt kurstaki) on young larvae
- Hornworms on tomatoes carry white cocoons — leave those; they are parasitised by braconid wasps
Paper wasps by target
What it eats and when it turns up differ by pest. Each page below is the picture for one target.