Technical Abstract: It is known that substantial boll weevil, Anthonomus grandis grandis Boheman, populations can survive mild subtropical winters in some habitats, such as citrus orchards. Our study shows that endocarp of the fruit from prickly pear cactus, Opuntia engelmannii Salm-Dyck ex. Engel.; orange, Citrus sinensis (L.) Osbeck.; and grapefruit, Citrus paradisi Macfad., can sustain newly-emerged adult boll weevil for more than five months, which is the duration of the cotton-free season in the subtropical Lower Rio Grande Valley of Texas and other cotton-growing areas in the Western Hemisphere. Cotton, Gossypium hirsutum L., and the boll weevil occur in the same areas with one or all three plant species (or other citrus and Opuntia species that might also nourish boll weevils) from South Texas to Argentina. Although adult boll weevils did not produce eggs when fed exclusively on the endocarps of prickly pear, orange, or grapefuit, these plants make it possible for boll weevils to survive from one cotton growing season to the next. This might also explain how individual boll weevils have been found far from cotton-growing areas. Potential impacts of our findings on boll weevil control are discussed.