Searching rate, mutual interference, and killing power were studied for two predator species, Coccinella undecimpunctata L. and Hippodamia tredecimpunctata L. (Coleoptera: Coccinellidae), provided with two prey species, Aphis gossypii (Glover) and Aphis punicae (Shinji) (Hemiptera: Aphididae), under laboratory conditions of 27 ± 2°C and 70 ± 5% RH. The searching rate of larvae and adult female C. undecimpunctata was higher than that of H. tredecimpunctata. Both C. undecimpunctata and H. tredecimpunctata exhibited higher searching rates when fed on A. gossypii than when fed on A. punicae. Larvae and adults of C. undecimpunctata showed higher searching rates than H. tredecimpunctata on both prey species. Mutual interference values for larval stage of both C. undecimpunctata and H. tredecimpunctata were higher than those for adults. For H. tredecimpunctata feeding on A. gossypii, respective values were 0.148, 0.190, 0.118, 0.070, and 0.069 for 1^st, 2^nd, 3^rd, 4^th larval instars and adults, respectively; while these values were 0.161, 0.167, 0.218, 0.140, and 0.058 on A. punicae, respectively. In conclusion, our laboratory data suggest that C. undecimpunctata might be a more efficient predator of A. gossypii and A. punicae compared with H. tredecimpunctata.