European paper wasps rear their young on live insects. They have become one of the most important natural controls of many kinds of Colorado garden insects. Most commonly they feed on caterpillars, including the larvae of hornworms and cabbageworms in the Colorado vegetable garden. On trees and shrubs tent caterpillars and sawfly larvae are commonly taken prey.
The European paper wasp is a black insect marked with yellow that is commonly mistaken for western yellowjacket. European paper wasp is slim in comparison to the somewhat blunter, more compact body form of yellowjackets. The long hind legs of paper wasps also tend to trail below when the insects are in flight unlike yellowjackets. They do not produce the nuisance problems for outdoor dining that are typical of western yellowjacket.
Check the Colorado State University Extension website for additional information and more photos of European paper wasp.
[European paper wasp photo credit: Whitney Cranshaw, Colorado State University, Bugwood.org]