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Gardeners can take steps to stop the Japanese Beetle

The Japanese beetle is currently under quarantine in Colorado.  The Colorado Department of Agriculture, in conjunction with the US Department of Agriculture and the Colorado Nursery and Greenhouse Association (CNGA), are working diligently to ensure that future introductions of this pest are prevented.

Japanese beetle (Popillia japonica) is an insect pest that is not native to Colorado and can cause significant damage to landscape plants, turfgrass, and fruit trees. Originally introduced from Asia to the Eastern U.S. in the early 1900s, the beetle has slowly managed to expand its range westward.

Japanese beetle is most frequently moved from state to state in infested nursery stock and soil.  Currently, all trees, shrubs, sod and ornamental grasses brought into Colorado from infested states to the east, must first be certified by the state of origin to be free of Japanese beetle.  While it is illegal to knowingly move plants and soil infested with Japanese beetle into the state, it is also illegal to knowingly move plants and soil infested with Japanese beetle within the state.

CDA monitors nurseries and sod farms for Japanese Beetle.

Monitoring (trapping) for Japanese beetle populations in Colorado Nurseries and Sod farms has been occurring since the late 1990s.  Thirty-six nurseries and sod farms take part in this program.   No established Japanese beetle infestations have ever been detected in nurseries or sod farms in our state.

CDA inspects nurseries and sod farms.

Anyone who sells nursery stock (nurseries, sod farms and landscape contractors) is required to register with CDA; of the 1,711 registered nursery dealers and growers in our state, 90 percent are inspected annually.  During inspections, CDA checks the condition of the plants offered for sale and verifies that any nursery stock imported from Japanese beetle quarantined areas are certified beetle free.  A list of registered nurseries and landscape contractors can be found at and click on “Nursery Program.”

With the support of the Colorado Nursery and Greenhouse Association, CDA requires that all plant material imported from states East of Colorado, including New Mexico, must meet Japanese beetle quarantine criteria.  Commercial nurseries, sod farms and landscape contractors are making sure the stock they import meets the quarantine criteria.  Those that do not ensure that imported stock meets the quarantine are subject to fines.

What are their favorite plants?

Japanese beetle larvae prefer to feed on the roots of grasses, such as those found in lawns or in ornamental beds.  The adult beetle has a wide range of plants it prefers including grapes, roses, hollyhocks, black walnut, apples, crabapples, peach, cherry, plum, lindens, mountain ash and lombardy poplar.


July 8 — 10 a.m., 4-H Entomology project.

July 8 — Noon, Mountain View Homemakers.

July 8 — 6 p.m., 4-H Lamb project.

July 8 — 6:30 p.m., Shady Pine Club.

July 9 — 2 p.m., Colorado Mountaineers Club.

July 9 — 2:15 p.m., Wolf Creek Wonders Club.

July 9 — 3:15 p.m., 4-H Goat project.

July 12 — 3 p.m., 4-H Beginning Sewing project.

July 12 — 6 p.m., 4-H Rocketry, Unit 1 project.

July 12 — 6 p.m., 4-H Livestock Committee meeting.

July 12 — 7 p.m., 4-H Swine project.

July 13 — 6 p.m., Rocky Mountain Riders Club.

July 13 — 6 p.m., 4-H Livestock Weigh-in.

July 13 — 6:30 p.m., Pagosa Peaks Club.

Check out our webpage at for calendar events and information.