Submitted to: Prairie Naturalist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/31/2003
Publication Date: 12/1/2003
Citation: HESLER, L.S. LARGE SUMMER POPULATION OF MULTICOLORED ASIAN LADY BEETLE IN NORTH DAKOTA. PRAIRIE NATURALIST 35: 287-289. 2003.
Interpretive Summary: I found multicolored Asian lady beetles (MALB)to be extremely abundant on American elm trees in Valley City, Barnes County, North Dakota, on July 14, 2002. Several life stages of MALB were present on American elm throughout the town. All adult MALB observed had orange to orange-red wing coverings with varying degrees of black spots, which is typical of MALB color forms in eastern North America. MALB accounted for most of the lady beetles found on the American elm trees, and aphids that had infested the elms served as prey. My observation represents the first record of MALB in North Dakota, and it further documents westward range expansion of this exotic species.
Technical Abstract: I found Harmonia axyridis (Pallas), multicolored Asian lady beetles, extremely abundant on American elm trees in Valley City, Barnes County, North Dakota on July 14, 2002. Adults, pupae, and larvae of H. axyridis were present on American elm throughout the town. All adult H. axyridis observed had orange to orange-red elytra with varying degrees of black maculation ranging from maculae absent to large and slightly coalescent, consistent with the typical color forms of H. axyridis in eastern North America. Harmonia axyridis accounted for the vast majority of lady beetles found on American elm, and an aphid, Tinocallis ulmifolii (Monell), served as its principal prey. My observations represent the first record of H. axyridis in North Dakota and further document westward range expansion of this exotic species.