As part of a comprehensive study of cicada-killer wasps (Sphecius spp.), we investigated the species and sex of their cicada prey. The 5 New World Sphecius species capture a total of 8 genera (Diceroprocta, Magicicada, Neocicada, Pacarina, Quesada, Tettigades, Tibicen, Uhleroides) and 38 species/subspecies of cicadas in the U.S.A., Cuba and Argentina. S. speciosus, the best-studied species, captures cicadas of 5 genera (Diceroprocta, Magicicada, Neocicada, Quesada, Tibicen,) and 30 species/subspecies, showing no significant overall prey sex bias. At specific sites where more than 50 cicada prey were recorded, the male:female ratio of 6 species brought to nests by Sphecius females varied between 0.524 and 2.259; Chi-square analysis revealed a significant male bias in overall Sphecius spp. prey sex ratios at these sites. The reported significant local variations in prey sex ratios are likely to be due to temporal variations in sex ratios of cicadas available to these opportunistic wasps.