Nymphs of all instars and adults of a lygaeoid bug, the myodochine rhyparochromid Cnemodus mavortius (Say), were collected from fallen pine cones, mainly those of longleaf pine (Pinus palustris Mill.; Pinaceae), at 22 sites in the southeastern United States (Alabama, Georgia, North Carolina, South Carolina). Nymphs and adults of C. hirtipes Blatchley were found in fallen pine cones at eight sites in Florida. Nymphs (occasionally >20/cone; n = 5) of all instars, exuviae, and teneral nymphs and adults were observed in cones, suggesting more than incidental and ephemeral occupancy by species of Cnemodus. The bugs might use the labium to transport seeds of pine and other plants to the shelter of cones before they begin to feed, obtain nutrition from pine seeds that remain in fallen cones, or feed on seeds of grasses or other plants that lodge in cones. Fallen cones could be used for overwintering and oviposition but might be most important for allowing the bugs to minimize desiccation in xeric habitats characterized by high soil-surface temperatures, especially if nymphs cluster in cones. Other heteropteran species were infrequent inhabitants of fallen pine cones: the rhyparochromids Eremocoris setosus Blatchley (Florida, Georgia, South Carolina), Neopamera bilobata (Say) (Florida), and Ozophora trinotata Barber (Florida); and the largid Arhaphe carolina Herrich-Schaeffer (South Carolina). We also record C. mavortius from crowns of bunchgrasses in southern states (Georgia, North Carolina, Oklahoma, South Carolina, Texas) and C. hirtipes from bunchgrasses in Florida.