There are many examples of insects and diseases that are not native to North America which were introduced at some time to our land. Some of these pests did not have any natural enemies on this continent, and they spread at various rates unopposed. A classic example of an introduced disease is the Chestnut Blight, which essentially eliminated the native chestnut trees from eastern North America.

There are many introduced insect pests, but one of the most well-known is the Japanese Beetle. It was first found in New Jersey in 1916. Today, it is found in almost all the states east of the Mississippi River and at least eight states west of the Mississippi, including Missouri.

The first occurrence in Missouri was reported in 1934 in St. Louis. Today it is found in several other locations around Missouri, including at least one report that I am aware of in Southeast Missouri.

Japanese Beetles are not picky eaters, and are known to feed on more than 400 species, including trees, shrubs, flowers, fruits, vegetables, field crops, and turf. In high numbers, they can skeletonize leaves, resulting in a plant with only a framework of veins where the leaf should be. They also feed on the roots of plants, including lawns and golf courses.

Japanese Beetles have a complete life cycle, which means they have an egg stage, a larval (grub) stage, a pupal stage, and finally an adult stage. Feeding damage is made by both grubs and adults.

They overwinter as grubs about six to eight inches below the soil surface. In the spring they become active, feeding on roots. After pupating, they emerge as adults in June, and start feeding again. After mating, the females burrow into the ground to lay eggs. A single female may lay as many as 60 eggs.

Japanese Beetle adults are metallic green in color, with a copper-colored wing sheathes on their back. On each side of their abdomen, they have six white tufts. They are not large, typically measuring about 3/8 inch in length.

Insecticides are available to control Japanese Beetles, but they can be difficult to eliminate because of their potentially large numbers and ability to feed on so many different kinds of plants. Some attempts are being made at using biological controls, such as parasitic flies and wasps. Earlier, attempts were made to quarantine areas, but these proved futile. Even trapping did not work, as it was found to actually attract more beetles to the area where the traps were located.

I mentioned earlier that they have been observed in Southeast Missouri. I discussed this recently with Anthony Ohmes, Agronomy Specialist for Extension in Mississippi County, Missouri. He reports seeing damage in soybean fields on a regular basis. He has heard of at least one field where it was sprayed after the farmer felt that the Japanese Beetle threshold had exceeded the allowable limits. Two years ago, Anthony saw the first reported occurrence in Mississippi County. Three years ago, they were unheard of there.

They have also occurred in other counties along the Mississippi River. I have heard reports of bad infestations in grape vineyards in Ste. Genevieve County.

So will they move into the rest of Southeast Missouri? Time will tell. I would suggest that you keep an eye out for them, and if you would like assistance in identification, please don't hesitate to give us a call. If you would like more information, we have a copy of a USDA publication on the topic. Call 573-888-4722, and ask for, "Managing the Japanese Beetle: A Homeowner's Handbook."