Discrepancies in reports on the presence of spined soldier bug, Podisus maculiventris (Say) (Hemiptera: Pentatomidae), in the western region of the USA, and morphological variations of the species brought into question whether the species existed west of the Rocky Mountains. In this study, morphological variations in color and size were observed between two geographically isolated populations from Missouri and California. Differences were determined in color, weight, and size measurements. However, all crosses and backcrosses produced viable progeny of both genders and the crosses were maintained as inbred lines for 16 generations. These results indicated the two populations are closely related.