The phenology, spatial distribution, and reproductive ecology of Anthonomus palmeri Jones & Burke and Anthonomus townsendi Jones & Burke (Anthonomus grandis species group; Coleoptera: Curculionidae) were studied over a period of 2 yr on three species of Hampea (Malvaceae: Gossypieae) in southern Mexico. These weevil species are closely related to the cotton pest Anthonomus grandis Boheman, and Hampea is the probable ancestral host of the group. The three species of Hampea studied, H. montebellensis Fryxell, H. longipes Miranda, and H. mexicana Fryxell, are small to medium sized, dioecious trees that occur in montane habitats above 500 m in elevation in the central portion of the state of Chiapas, Mexico. All three species had limited reproductive periods, with flowering beginning with the rains during June and ended during August for H. longipes and H. mexicana and mid-September for H. montebellensis. Only male flower buds were found infested with weevils. Infestation levels of male flower buds were relatively low (<30%) for all species and years except for H. longipes during 1990. During that year, >90% of the buds of H. longipes were infested. Weevil populations on each of the Hampea species had specific and distinct size preferences in the flower buds chosen for ovipostion. No flower buds were found with multiple oviposition punctures, indicating that female weevils were able to distinguish previously infested flower buds and avoided ovipositing in them. Weevils were aggregated on branches with the greatest number of buds. The ecology of the species of Anthonomus studied is compared with their close relative, the cotton boll weevil when on cotton and wild hosts, and the factors that may have lead this one species to be a pest of cotton are discussed.