 Nevertheless, the ratio between flight muscle mass and body mass is the same for both sexes.Distinguishing "S. grandis" from the other four New World species of "Sphecius" ("S. convallis", "S. hogardii", "S. speciosus", "S. spectabilis") is difficult.The female "S. convallis" was originally distinguished from the female "S. grandis" by the yellow marks from the first to third gastral tergites on "S. convallis" and yellow marks on all tergites for "S. grandis".