New native Bacillus thuringiensis strains induce high insecticidal action against Culex pipiens pallens larvae and adults

Table 4 Toxicity of preparations of spores and crystal mixture from eight B. thuringiensis isolates against third-instar larval stage of C. pipiens pallens after 24 h post-treatment

B. thuringiensis-code	LC₅₀ (µg/ml) ^a	LC₉₅ (µg/ml) ^a	CFU/µg × 10^{7 b}
A2	7.1 ± 1.2	40.7 ± 6.6	5.1 ± 0.3
A4	1.4 ± 0.5	15.3 ± 4.4	1.5 ± 0.1
A8	16.6 ± 2.7	99.1 ± 12.4	2.3 ± 0.2
A10	3.7 ± 1.1	27.1 ± 4.5	1.7 ± 0.1
B6	28.5 ± 4.2	130.3 ± 14.2	9.3 ± 0.4
C2	6.4 ± 2.7	50.2 ± 3.4	2.3 ± 0.2
C4	14.7 ± 3.9	59.4 ± 4.5	1.9 ± 0.3
C5	10.2 ± 3.4	84.5 ± 7.7	2.1 ± 0.1

^a LC₅₀ and LC₉₅, Lethal Concentration that kills 50 and 95% of larval population (n = 25), respectively (calculated by Probit analysis and reported with 95% confidence intervals)
^b CFU, colony forming unit (mean ± standard error). Each bioassay comprised five concentrations, three replicate for each concentration, and were repeated five times

ISSN: 1471-2180