Date of this Version
Journal of Entomological Science 41:1 (January 2006), pp. 84-86.
The seven-spotted lady beetle, Coccinella septempunctata L., and the multicolored Asian lady beetle, Harmonia axyridis Pallas, are exotic Coccinellidae (Coleoptera) that are regularly encountered in southeastern Nebraska. Harmonia axyridis, a native of eastern Asia, was first reported in an established population near Abita Springs, St. Tammay Parish, Louisiana, in 1988. It was hypothesized that the introduction was accidental through commerce in Louisiana and not from introduction for biological control. Coccinella septempunctata, a native of Eurasia, was introduced for biological control several times and at a variety of locations across North America during the last century. As is the case with many exotic species there is concern that introduced lady beetles may be reducing or replacing populations of native species. . . .
. . . We acknowledge that the increases seen in the abundance of the exotic lady beetles were not statistically significant and could not be interpreted as an indication of a trend of increasing abundance. However, the data show that both C. septempunctata and H. axyridis were collected more frequently in alfalfa between 2001 and 2003 than they were between 1992 and 1995. We further acknowledge that numerous biotic and abiotic factors could have influenced the abundance and collection rates of the Coccinellidae. However, given evidence from other areas of North America, the possibility exists that the abundance of exotic lady beetles could be increasing in the Midwest. Our data serve as a record of the current abundance of these exotic species and could be used for comparison with future studies examining the influence of exotic lady beetles on native species.