Dominant Inheritance of Plutella xylostella selected with Flufenoxuron

 Dominance study was a petition needs to measure insecticide resistance problems to a notorious pest as Plutella xylostella and for IRM strategy planning success. Flufenoxuron insecticide was chosen for doing a laboratory selected strain for some resistance assessments. Studies on cross resistance of flufenoxuron resistant strains revealed a slight tolerance to lambdacyhalothrin, alphacypermethrin, thiocyclam and chlorfenapyr but no cross resistance to dimethoate, imidacloprid. Resistance stablility examined in both the flufenoxuron selected strain and the backcross selected x susceptible in the absence of exposure to insecticides, results revealed that the mortality were declined slowly at F3, F5 and F7. Results of reciprocal crossing experiments suggested that flufenoxuron resistance was inherited as an incomplete recessive trait. Values of the degree of dominance were estimated -0.63 and -0.66 for F1 larvae with resistant and susceptible female parents, respectively. Results of bioassays on F1 progeny of the backcrossed with the resistant parent strain and the F2 generations suggested that resistanceautosomaly inherited and might be controlled by some loci. Analysis of probit lines from F1 reciprocal crosses indicated that resistance to flufenoxuron was inherited autosomaly as an incompletely recessive and probit lines showed no plateau at 50% mortality (probit = 4.0) and 3.4 for F2 at 25-75% mortality. The x² analysis of response ratio statistics of a monogenic model from F1 susceptible back crosses suggested that more than one locus is responsible for resistance to flufenoxuron.