Inheritance pattern of the flightless characteristic in Harmonia axyridis

Abstract

The genetic basis of the flightless characteristic in Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) was studied using two crossbreeding experiments to verify the inheritance of the flightless character which may be relevant if mating with wild populations takes place. In the first experiment, the segregating population (F2) was obtained by random mating within each F1 line. The proportion of flightless individuals reached 24–29% in the F2 generation. In the second experiment, the F1 individuals were crossed with the flightless individuals to develop a backcross (BC) population, which showed that the proportion of flightless individuals reached 33–59% in the BC population. Although the quantitative variation of flight ability in H. axyridis could also be due to a large proportion of loci with small effects, our results suggest that the flightless mutation is largely controlled by a single locus and that only H. axyridis individuals homozygous for the recessive alleles show the flightless characteristic.