Genetics of diazinon resistance in larvae of Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae)

Abstract

AbstractThe response of F1 larvae from reciprocal crosses of susceptible × organophosphorus-resistant strains of Lucilia cuprina (Wied.) to diazinon was intermediate in relation to that for larvae from the parental lines to the chemical. Exposure to a concentration of 0·4 p.p.m. diazinon for 24 h was lethal to susceptible larvae. Close agreement with 1:1 ratios of susceptible: hybrid resistant larvae was obtained when larvae from a repeat backcross series were exposed to 0.4 p.p.m diazinon in each generation. Additionally, there was correspondence between response lines for larvae of backcrosses 1 and 3. This information, plus the recovery of a homozygous-resistant sub-strain by exposure of F2 larvae to a level of the chemical that discriminated against susceptible and hybrid genotypes, suggest that diazinon resistance in the larvae is due to a major allele.