EL DORADO SPRINGS, Mo. (AP) — The Saint Louis Zoo and other conservation groups have been working to restore the population of an endangered beetle in southwest Missouri, and the effort appears successful so far. The zoo, the Nature Conservancy, the U.S. Fish and Wildlife Service and the Missouri Department of Conservation have been collaborating on the plan to improve the population of American burying beetles at Wah'Kon-Tah Prairie in southwest Missouri. Crews brought about 600 of the large red and black beetles to the 4,040-acre prairie this past week to add to the population reintroduced at the site last year, the Nature Conservancy said in a release. "It's very encouraging and rewarding to see these very positive results at such an early stage of the reintroduction," said Bob Merz, director of the zoo's Center for American Burying Beetle Conservation. The zoo breeds the beetles and monitors the reintroduced population. The Fish and Wildlife Service listed the American burying beetle as endangered in 1999. Once found in 35 states, the beetles are now found naturally in seven locations. Until the reintroduction, they hadn't been seen in Missouri since the 1970s. The groups also plan to bring additional beetles to the site each year for the next three years. Burying Beetle image