Abstract: DNA markers of Bemisia tabaci (Gennadius) were developed to detect the remains of whitefly in the gut of Propylaea japonica (Thunberg) reared in lab and various predators collected in cotton fields. An approximately 350 bp DNA fragment of B. tabaci, absent in other closely related prey species, cotton and in the predators banding pattern, was identified by random amplified polymorphic DNA (RAPD) analysis. After cloning and sequencing the target fragment (347 bp, AY841800 in GenBank), one pair of sequence-characterized amplified region (SCAR) primers was developed, amplified single band of ca. 240 bp. Specificity tests performed with this pair of primers showed the presence of the band for B. tabaci in all stages and in both sexes. The target DNA fragment of B. tabaci was equally detected in P. japonica adult fed with 10 red-eyed nymphs of B. tabaci and in all predator species collected in cotton fields. The detection rate of B. tabaci DNA in predators, such as the larvae of P. japonica, Harmonia axyridis, Chrysopa spp., adult Orius sauteri and spiders, was over 50%.

Key words: Bemisia tabaci, RAPD-PCR, SCAR markers, Gut content analysis