Relative fitness of resistance to pyriproxyfen in Culex pipien pallens

ObjectiveTo compare the difference of biological characters between pyriproxyfen-resistance population and susceptible population.

MethodsThe biological test was used in this study to compare the difference of larval survival, pupation, adult emergence, relative fitness and cumulative developmental rate.

ResultsThere was no significant difference in larval survival and very significant difference in pupation, adult emergence and general survival rate between the two populations.The pupation rate of resistance population was 46.01%, and that in susceptible population was 98.34%.The initial time of incubation and emergence in resistance population was all later than that in susceptible population.The initial hatching time and pupation time was delayed by 12 h and 24 h, respectively.And the duration of pupation was prolonged by 108 h.The resistance population had a fitness of 0.61 relative to the susceptible one.

ConclusionThe pyriproxyfen-resistance population has unfavorable reproductive character, which can be used for resistance control so as to delay the resistance development by stopping or rotating the use of insecticides.