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Submitted to: Brookings Register
Publication Type: Popular Publication Publication Acceptance Date: 10/18/2006 Publication Date: 10/18/2006 Citation: Hesler, L.S. 2006. What's Buggin' You. Brookings Register. Brookings, South Dakota. October 18, 2006. pp. A1, A5. Interpretive Summary: Technical Abstract: Recent establishment of an exotic insect known as the multicolored Asian lady beetle in North America threatens to tarnish the good reputation of a generally beneficial group of insects. Lady beetles, commonly called ladybugs, are one of the favorite and most widely recognized kind of insects. They are often depicted favorably in children's books, fables, and nursery rhymes. Some catch the fancy of artists due to black spots and bands that contrast with vivid red or orange forewings, though many lady beetles are dark with few or no markings. More importantly, lady beetles are beneficial because they provide biological pest control in gardens, orchards and crop fields. Most prey on pests as adults and in their immature, caterpillar-like larval stages. There are about 500 species, or different kinds, of lady beetles in America north of Mexico, and about 65 species in South Dakota. The vast majority are native. The Asian lady beetles have been getting the most attention lately. That's because of unappealing behaviors that offset their benefits of preying on crop pests such as soybean aphids and European corn borer larvae. Chief among their negative behaviors is a knack for invading houses and other buildings to overwinter. They are most problematic in the fall when large numbers enter homes, and in late spring when they leave. Once inside, Asian lady beetles stain curtains and light colored fabrics and surfaces, and give off an unpleasant odor when handled. Many may die in windowsills, doorways, and poorly insulated rooms and attics, leaving a mess for residents to clean up. The beetles sometimes bite, although their bites are more like a mild pinch and not serious. Asian lady beetles are also a pest of ripened fruit in the fall--able to break the soft rind of fruits like grapes and peaches or find their way into cracks in the rinds of apples and pears. The beetles become stowaways when fruit is brought inside to make juices, jams and jellies. Keeping Asian lady beetles out of homes requires that windows be effectively screened and that other points of entry are also screened or sealed. Bunches of fall-ripened fruit from gardens and home orchards should be checked and any beetles removed. Several insecticides are also registered for application to the exteriors of buildings to prevent entry of Asian lady beetles. Asian lady beetles found congregating in homes may be vacuumed and discarded. An Asian lady beetle was discovered in South Dakota in autumn 1996 near Brookings. After a two-year gap, many more Asian lady beetles were found in 1999 in and around Brookings. Since then, the number of beetles has steadily increased, and they have spread across the state. The Asian lady beetle was found near Highmore in central South Dakota by summer 2002, and out west near Nisland by February 2004. The Asian lady beetles in South Dakota came from a population that spread out from an initial point of detection in North America near the port of New Orleans in the late 1980s. A second accidental introduction on the West Coast about the same time likely explains a disjoint distribution of Asian lady beetles west of the Rocky Mountains. Asian lady beetles have been imported into North America on several occasions since 1916 for biological control of various tree pests. Intentional releases of Asian lady beetle were made in several states including California, Washington, Massachusetts, Georgia and the province of Nova Scotia, Canada, but never in South Dakota or other states in the northern Great Plains. All releases apparently failed to establish Asian lady beetle in North America. Since arriving in South Dakota, Asian lady beetles have emerged as one of the most abundant insect predators in soybean fields infested by soybean aphid. Despite their abundance in these fields, lady beetles and other natural enemies have only provided partial--and |
