European Paper Wasp | 4K
Channel: Nature Jedi
Date: 2023-12-21

How paper wasps affect bees
Paper wasps are common and well-known predators of insects. But one species, the European paper wasp, is causing concern for native bees.

European Paper Wasp is an Old World species that has a native range from Europe to China. The species is by far the most common Polistes in Western Europe.

A highly successful colonizer, the European paper wasp has rapidly increased its distribution in the United States since its introduction in the late 1970s.

The European paper wasp is about ¾ of an inch long. It has a black body with yellow markings and is slender-bodied with a “thread waist”.      Environmental Impact:
European paper wasps compete with native paper wasps, primarily northern paper wasps (Polistes fuscatus) for food and nesting sites, but the impact varies by locality. In Michigan, European paper wasps have completely replaced northern paper wasps in some areas, while in Ontario the two species exist at an approximately 1:1 ratio. Elsewhere, such as in South Dakota, European paper wasps are present but at a lower frequency compared to native species.

The displacement of native paper wasps by European paper wasps has been attribute to multiple factors, which can differ across regions and produce these variable outcomes:

European paper wasps establish colonies earlier in the season, which means workers forage earlier and can lead to faster colony expansion. However, in colder areas, including Pennsylvania, this can expose them to late-season freezes that result in a high level of mortality.
Earlier nest establishment and more workers may allow nests to more easily repel birds that predate wasp larvae.
European paper wasps tend to build nests in more enclosed sites, which may protect them from predation and the elements. However, in areas where fewer enclosed areas occur (e.g., the Great Plains), European paper wasps may be restricted to nesting in buildings and other human-altered habitats.
European paper wasps have a more varied diet – native paper wasps feed exclusively on caterpillars while European paper wasps feed on caterpillars but also other small, soft-bodied insects – which may increase early and rapid larval development.
European paper wasp queens tend to produce more workers compared to native paper wasp species even when they nest in the same habitats
European paper wasps experience lower parasitism compared to native paper wasps
There is also evidence that European paper wasps have a detrimental effect on native caterpillars. Multiple studies have found they negatively impact monarch caterpillar populations, especially in urban areas where wasp populations are high and caterpillars are concentrated into small areas. Their spread across North America may therefore represent an underappreciated negative effect on monarch populations.