Resistance development in mosquito larvae Culex pipiens to the bacterial agent Bacillus thuringiensis var. israelensis

Mosquito larvae of Culex pipiens were subjected repeatedly to selection pressure with the bacterial agent Bacillus thuringiensis var. israelensis (B.t.i.) in the laboratory. Only 2.78-fold increase in tolerance to B.t.i . was induced in C. pipiens as a result of 20 generations of selection. The tolerance of C. pipiens to B.t.i. decreased by about 58% after stopping the selection for three generations. Larval selection with B.t.i. caused a reduction in the reproductive potential of mosquito adult survivors but did not affect the adult longevity and the time of blood meal digestion ingested by female mosquitoes.