Forty strains of Bacillus thuringiensis Berliner (Baciliales: Bacillaceae) that were isolated from corpses of Hemiptera were assessed against Myzus persicae (Sulzer) (Hemiptera: Aphididae), an aphid that is considered one of the most destructive pests affecting the agricultural economy. Seventeen strains were significantly different from the control according to the LSD test (α = 0.05). They caused mortality rates ranging from 64.4 to 88.9% at 10 ng/μL total protein concentration, and from 71.1 to 91.1% at 100 ng/μL total protein concentration. The virulence (LC50) of these 17 strains was calculated, and 5 strains showed the highest virulence (GP777 = 10.63 ng/μL, HD1 = 9.10 ng/μL, GP528 = 7.86 ng/μL, GP402 = 7.12 ng/μL, and GP300 = 6.88 ng/μL). These strains have the potential to be used as an alternative to control M. persicae under field and covered conditions.