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In our attempt to write timely articles, it's time to start looking for rose chafers. They are members of the scarab beetle family and are related to the Japanese beetle, and their life cycle is similar. Rose chafers were first reported as a grape pest as early as 1810. Later they ranged to include a wide assortment of host plants. They are found primarily in the northeastern United States, but they also occur south at least to North Carolina and west to Colorado.

The adult rose chafer is a long-legged, slender, fawn-colored beetle about 3/4 inches long. The head and thorax are reddish-brown and the body undersurface is black. As the fine yellow hairs are worn off, the beetles change from fawn to gray color. The larva or grub is a typical scarab grub, closely resembling those of the common white grub or June beetle and Japanese beetle.

The larvae are yellowish-white with a pale brown head capsule and three distinct pairs of legs. The body is held in a curved "c"-shaped position. The larvae of these grubs may be distinguished by the pattern of hairs at the tip of the abdomen.

Rose Chafer adults appear suddenly, usually in large numbers about mid-May. Soon after emerging from the ground they mate and begin feeding.

The female can produce up to three dozen eggs in sandy or grassland soil, and they hatch in one to three weeks. The young larvae begin feeding on tender grass rootlets and by fall are nearly full grown.

Late in the fall they dig themselves an earth home below the frost line preparing for the winter. In the spring the nearly full-grown larvae work their way toward the ground surface and fly to their favorite host plants. Thus the cycle begins.

The host plants include the flowers of roses and peonies, new grapes and the leaves of grapes. They will also feed on apple, cherry, elder, and elm tree leaves. Other flowers include foxglove, geranium, hollyhock, hydrangea, poppy, Virginia creeper, and wisteria. The foliage of various broad-leaved plants is skeletonized. I didn't know until I researched for this article that rose chafers are poisonous to chickens and birds when eaten.

Control of this pest depends upon the severity of the problem and what plant it feeds on. For example, on grapes if there is severe infestation the blossom buds are often completely destroyed. This results in little or no grape production for that year. Population levels vary from year to year. Petal-full sprays for grape berry moths can also be used to control rose chafers.

In home gardens, rose chafer adults may be handpicked or jarred from small shrubs and flowers and gathered into a can, ground cloth, or inverted bumbershoot and then destroyed. This method is tedious and must be practiced daily in both the early morning and toward sundown, much like dealing with potato beetles.

If you take the chemical route, most foliage and flowers can be protected by spraying or dusting. However, insecticides will not fully protect roses, which unfold too fast and are especially attractive to beetles. When beetles are most abundant on roses, nip the buds and spray the bushes to protect the leaves. When the beetles become scarce, let the bushes bloom again. The timing is most important. Begin treatment as soon as beetles appear, before the damage is done. Japanese beetle traps are of no value. Also, using cheesecloth as a barrier over the plants doesn't seem to be as effective as once thought.

Insecticides such as acephate (Orthene), permethrin, carbaryl (Sevin), or malathion, seems to be most effective. As with any spray, read the directions and follow them carefully. Most rose chafers should be done feeding by the end of June.

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Ways to access information

Master Gardeners will be offering free plant clinics every Monday night from 4:30-8:00 at the Extension office in North Branch. Stop by 38780 Eighth Ave. (the Anderson Chiropractic Building) or call 651-674-4417 to speak with a Master Gardener.

www.extension.umn.edu/county/chisago Check out the 'Hot Topics' box in the middle of the page for current Chisago County Master Gardener news and events.

You can also click on 'Ask a Master Gardener' next to the cute little flower on the right hand side of the page. Here you can search 1000's of answers from Master Gardeners around the state. If you don't find your answer you can submit a question online or search for University publications.

Bell Museum of Natural History

For information about snakes, skunks, raccoons or other wildlife around your yard, call the wildlife information line at (612) 624-1374 or www.bellmuseum.org.

To see the latest Yard and Garden newsletter, go to: http://www.exten sion.umn.edu/yardandgarden/YGLNews/YGLNews.html.

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