Previous Next / Community Science: Japanese Beetle Survey Many of you might have seen pretty, shiny brown and metallic beetles in yards and parks, feeding in numbers on roses, Virginia creeper, or almost any other plant you can think of. These are Japanese beetles (Popillia japonica), a species of scarab beetle accidentally introduced to the eastern United States over 100 years ago. In the early 1990s, they arrived in the Denver area and for the last few years became a serious pest of ornamental plants and lawns. The adult beetles feed on hundreds of species of plants, preferring roses and vines. The larvae feed on the roots of well-watered lawn. The Museum is trying to determine how far the Japanese beetle has spread in Colorado and to compile a distribution map of all the records we can obtain. For this, we sought your help in the previous two years and received hundreds of samples delivered by many citizen scientists of all ages. This year, in 2019, we prepared a report to be published in a scientific journal, but a preliminary report showing most of the records on a distribution map was published by the Denver Post last year.