Diabrotica barberi Smith and Lawrence and Diabrotica longicornis (Say) (Coleoptera: Chrysomelidae) are sister species. D. barberi, the northern corn rootworm, is an important pest of corn in the U.S. Corn Belt; D. longicornis is a nonpest species that occurs in grassland habitats. The species’ ranges overlap in eastern and central Nebraska and Kansas, and observational data suggest that some habitat overlap occurs as well. Hybridization between the two species may occur under field conditions. Previous work has shown that hybrids formed from female D. longicornis and male D. barberi have life history traits comparable to individuals of the parental species. This study focuses on viability of offspring of these hybrids. Eggs were obtained from parental crosses (hybrids), parental-hybrid crosses (backcrosses), hybrid-hybrid crosses, and parental lines in 2006. Eggs were hatched in 2007, and various life history traits, which may contribute to overall fitness, were measured. Percentage egg hatch, total development time (neonate larva to adult emergence), and larval survival for each cross were recorded. Adult sex ratio and longevity were also documented. Female D. barberi x male D. longicornis crosses produced few viable offspring. However, life history traits characterized in this study were comparable between all other crosses and the parental species. Although unidirectional incompatibility occurs, hybrids of female D. longicornis and male D. barberi and their offspring, if they are produced in the field, may have no significant fitness disadvantage when compared to the parent species. Results are discussed within the context of the evolutionary significance to both species.