Differentiation of Aedes triseriatus and Ae. hendersoni (Diptera: Culicidae) based on the surface structure of the egg shell.

Abstract

Aedes triseriatus (Say) and Aedes hendersoni Cockerell are the most common tree hole-breeding mosquitoes in the United States. Both Ae. triseriatus and Ae. hendersoni are found throughout the eastern United States, from Minnesota to Maine, and southward to central Texas and Florida; however, the range of Ae. hendersoni extends much further west, leaving only Arizona, California and Nevada outside its U.S. range (Zavortink, 1972, Contrib. Am. Entomol. Inst. 8 : 1–206). Ae. hendersoni was once considered a variety of Ae. triseriatus , but Breland (1960, Ann. Entomol. Soc. Am. 53 : 600–06) proposed the elevation of Ae. hendersoni to specific rank based on morphological and chromosomal studies. When working with field populations of Ae. triseriatus in areas where Ae. hendersoni also may occur, caution must be taken to assure that the 2 species are distinguished. This is particularly important in studies concerned with mosquito-borne diseases. Ae. triseriatus is a known vector of the La Crosse strain of California encephalitis virus (Cramblett, Stegmiller & Spencer, 1966, J. Am. Med. Assoc. 198 : 108–12; Thompson & Inhorn, 1967, Wis. Med. J. 66 : 250–53; Masterson, Stegmiller, Parsons, Croft & Spencer, 1971, Health Lab. Sci. 8 : 89–96) and considered to be a potential vector of dog heartworm (Phillips, 1939, Am. J. Hyg. 29 : 121–29) and bird malaria (Huff, 1932, Am. J. Hyg. 15 : 751–54). The medical importance of Ae. hendersoni , however, is not yet known.