Table 2.

Larvicidal activity of B. sphaericus recombinant strains against C. pipiens subsp. pipiens (SPHAE) and C. quinquefasciatus (GeoR) larval populations resistant toB. sphaericus

Mosquito strainStrain (FWC)aLarvicidal activity (μg/ml)
LC50bLC90
C. quinquefasciatus 2297 (parental)134.0 ± 6.7c 383.6 ± 28.4
2297(pcyt1Ab1)6.0 ± 2.816.4 ± 8.8
C. pipiens subsp. pipiens 2297 (parental)193.2 ± 46611.4 ± 42
2297(pcyt1Ab1)14.1 ± 7.438.8 ± 18
2362 (parental)66.8 ± 24.9115.2 ± 65
2362(pcyt1Ab1)45.8 ± 7.8122.3 ± 67
2297 asporulated(pMK3)595d 7,806
2297 asporulated(pcyt1Ab1)215 ± 781,346 ± 944
B. thuringiensis SPL 407 (pcyt1Ab1)e 43.2 ± 21416 ± 219
  • a All strains are B. sphaericus, except as noted.

  • b LC after 48 h of larval exposure ± standard error; mean of three experiments.

  • c Result of two experiments.

  • d Result of one experiment.

  • e Purified crystals of Cyt1Ab1 protein.