• Korean journal of applied entomology
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• v.40 no.4
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• pp.321-326
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• 2001

Contribution of Wolbachia infection to fitness of a species (developmental time, adult life span, fecundity and ovipositional period) was measured in the susceptible and dicofol-resistant strains of two spotted spider mite, Tetranychus urticae Koch, on miniature roses. Based on ftsZPCR assay, Wolbachia infection was confirmed only in the susceptible strain. The susceptible strain had significantly higher fecundity (eggs/female) and shorter developmental times than the resistant strain. Longer adult life span and ovipositional period were observed in the susceptible strain. Fitness differences were appeared to influence dicofol resistance development. Similar measurements were performed with progeny from two reciprocal $F_1$crosses. Similar to other examples of cytoplasmic incompatibility induced by Wolbachia, subsequent cross between uninfected female and infected male spider mites were different from the other combination: a high egg mortality and a male-biased sex ratio. When the intrinsic rate of natural increase was calculated, the cross between uninfected female and infected male spider mites had a significantly lower rate($0.09\pm$0.01) than did the other combination ($0.20\pm$0.01). These results suggest that the dynamic and evolution of the fitness are closely associated with dicofol resistance and Wolbachia infection in the two spotted spider mites.