Three Insect Infestations Converging on Region


CAPE GIRARDEAU, Mo., June 16, 2011 — Three insects of concern are currently infesting southeast Missouri and threatening damage to plant life, according to Dr. Sven Svenson, assistant professor of agriculture at Southeast Missouri State University, and Dr. Kelly Tindall of the University of Missouri’s Division of Plant Sciences.

The Japanese beetle, the emerald ash borer and the gypsy moth are collectively attacking most of southeast Missouri’s major forest and landscape species and many commercially important food crops. Complete infestation is projected to occur in the area as a result of these infestations sometime within the next two to 25 years, according to Svenson.

In southeast Missouri, he said, “Trial areas are needed to identify species and cultivars of species that can survive and thrive in the presence of these pests.”

Information attained from the previously infested regions of the United States will aid in the successful selection of test species that can live despite the invading insects, he said.

Native insect species are also at risk of being affected by the spread of these insects.

“Any time a new insect enters an ecosystem, there is a possibility that the new insect can displace the native species,” said Tindall.

Chemical and physical control measures are available, but none are completely effective, and many of the treatments may have undesirable or unintended side effects, she said.

“All the insecticides that go out to get rid of the new insects could impact native species,” Tindall said.

Japanese beetle adults can feed on plants until they are completely defoliated, and beetle larvae damage grass species by feeding on roots. Emerald ash borer larvae feed on the inner bark of ash trees, disrupting the tree’s ability to transport water and nutrients, thereby killing the trees. The larval stage of the Gypsy Moth can consume all of the foliage from trees and other plants, with repeated defoliation eventually killing the plant.

Native to Japan, the Japanese beetle was first found in the United States in 1916 near Riverton, N.J. Spreading out from New Jersey, the minor front wave of Japanese beetles has already arrived in southeast Missouri. Japanese beetles attack corn, beans, grapes, peaches, black walnut, raspberries, blackberries, blueberries, peppers, tomatoes, peas, plums, cherries, apples, carrots and potatoes, which includes most of southeast Missouri’s major crop plants. Japanese beetles also attack hundreds of forest and landscape species, including maples, walnuts, elms, lilacs, arborvitae, viburnum, crape myrtle, hydrangea, wisteria, chrysanthemum, privet, coneflowers, primrose, hibiscus, hollies, daylilies and rhododendrons, which includes most of southeast Missouri’s major forest and landscape species, Svenson said.

The emerald ash borer was discovered in southeastern Michigan in 2002. The U.S. Department of Agriculture is already enforcing quarantine on the emerald ash borer in Missouri, but the quarantine has not successfully stopped the insect from spreading. Missouri’s first reported emerald ash borer infestation was in July 2008 at the Wappapello Lake Area in Wayne County, Missouri. Southeast Missouri’s native ash trees, including pumpkin ash, are at risk, including all ash trees used in urban, suburban and rural landscapes. The Missouri Department of Conservation cautions residents and visitors to not move firewood, to not plant ash trees and to learn to identify infestations.

Also known as the Asian gypsy moth, the gypsy moth originates from Europe to Asia and was introduced to North America in the late 1860s. It has been expanding its range ever since. The most popular plants Gypsy Moth larvae feed on are alder, maple, oak, apple, Douglas-fir, poplar, aspen, hawthorne, birch, larch, serviceberry, blueberry, linden, witch hazel, blue spruce, elm, pear, cherry, black gum, pine, chestnut, hemlock, cottonwood, hickory, sassafras and mountain ash. These represent most of southeast Missouri’s major forest and landscape species and many commercially important food crops, Svenson said.