PMC

A. Epistatic interaction detected between the sex-determining region (SDR) and the P2 QTL. The B allele was inherited from the female parent, and the A allele from the male parent. Females can undergo parthenogenesis independently of the allele carried at the P2 locus whereas males are only parthenogenetic if they carried the B allele at the P2 locus. B. Epistatic interaction between the P3 and P2 loci. The combination of B alleles at both P2 and P3 loci increases the parthenogenetic frequency. Note that parthenogenesis frequencies were calculated using both males and females.

Crossing strategy with BILs for developing an NIL of Frankliniella occidentalis that is resistant to spinosad. ^aF1P1, offspring of F1 by parthenogenesis; ^b, Add Ivf03 female in every cycle.

Both the parthenogenetic female and gynopara reproduce in parthenogenesis, but their body, ovary and ovarioles are discriminated. The sexual female has divergent morphology from other two morphs and produces eggs. Scale bars: body, 0.2 mm; ovary and ovariole, 0.1 mm.

A) After seven generations of introgression, between 95–99% of the Wolbachia-dependent asexual nuclear background was replaced by the sexually reproducing nuclear background. At each generation of the introgression, we used virgin wasps to assay for sex ratio (a proxy for successful Wolbachia-mediated parthenogenesis) and fecundity prior to mating with a sexual male. All offspring were screened for zygosity, allowing for the identification of females produced via fertilization rather than Wolbachia-mediated parthenogenesis. This scheme was performed 3 independent times to generate 3 isofemale lines. B) Wasp fitness and C) efficiency of Wolbachia-mediated parthenogenesis at each generation of introgression. Sex ratio is denoted as the proportion of female offspring.