VARIATION IN ELYTRAL MACULAR FORMS OF COCCINELLA SEPTEMPUNCTATA L. (COLEOPTERA: COCCINELLIDAE) IN NORTH AMERICA

Coccinella septeinpunctata L. is a widespread Palearctic species that has been introduced several times into North America within the last century. It is generally considered monomorphic with seven elytral maculae in North America. In this paper, we document variation in elytral macular patterns of C. septempunctata based on examination of 674 (567 North American and 107 Palearctic) specimens of C. septempunctata and 382 digital submissions of North American C. septempunctata. Two beetles lacked apical maculae, and 18 beetles had paired humeral markings. Humeral markings were consistent in position and typically had less-dense black pigmentation than maculae. Sixteen of the 18 beetles with paired humeral markings were from 11 states in the United States, one was from Alberta, Canada, and one was from Italy. Some specimens had asymmetrical elytral markings that included pock marks, irregular fuscous markings, or both. Nineteen specimens of C. septempunctata (19 North American, 1 Palearctic) and 16 C. septempunctata in digital images had asymmetrical markings. Some beetles with paired humeral markings also had dark pock marks or irregular fuscous markings. We recommend examining additional C. septempunctata from various locations to accurately estimate frequency and pattern of variation in elytral macular forms. Possible causes and implications of variation in the elytral maculae of C. septempunctata are discussed.