GENOTYPE, ENVIRONMENT AND THE ASYMMETRY PHENOTYPE - DIELDRIN-RESISTANCE IN LUCILIA-CUPRINA (THE AUSTRALIAN SHEEP BLOWFLY)

Dieldrin-resistant (Rdl/Rdl and Rdl/+) and susceptible (+/+) phenotype s of Lucilia cuprina were scored for departures from bilateral symmetr y for bristle characters after development at different temperatures, larval densities or concentrations of dieldrin. The asymmetry phenotyp e of resistant flies was dominant and independent of developmental tem perature and larval density. The asymmetry of susceptibles increased f or temperatures and larval densities above and below standard rearing conditions. A positive correlation was observed between asymmetry scor e and dieldrin concentration for all genotypes. The susceptible phenot ype did not attain the asymmetry score of resistants in any environmen t. Resistant phenotypes showed an antisymmetric pattern in each enviro nment; fluctuating asymmetry was observed for susceptibles. The releva nce of the results of genetic and general or specific environmental st resses to estimates of developmental perturbation is discussed.