Populations of the boll weevil Anthonomus grandis Boheman are presently under an eradication program in the United Status but the insect still remains a key pest in most of the Americas. The insect probably has its origins in southern Mexico or Central America, where it has several wild host plants and closely related species. The objective of the present study was to determine and compare the genetic variation of the sequences of the transcribed ITS2 spacer region from populations from the United States and Mexico, including those on wild, as well as, cultivated host plants. Sequence data of ITS2 indicated that it was composed of 718 characters of which 539 were constant and 131 were variable, of which 48 were informative for parsimony analysis. Initial results indicated that weevils from wild cotton in Arizona on Gossypium thurberi populations were more closely related to populations on wild hosts (Hampea spp.) in southern Mexico than from populations on cultivated cotton from southern Texas and northeastern Mexico. In addition, there was greater variation among the Texas and northeastern Mexico populations, despite close proximity, than between the thurberia and Hampea populations. Further analysis of populations from other regions and hosts will be presented.