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Bemisia tabaci (Gennadius) is an important pest of agriculture and horticulture crops that includes many morphologically indistinguishable biotypes. Molecular markers can provide a scientific method to rapidly identify biotypes. In this study, we attempted to develop specific primer sets for rapidly and stably identifying various biotypes of B. tabaci. We developed sequence characterized amplified region (SCAR) markers for each of six B. tabaci (Gennadius) biotypes (A, B, Q, Nauru, An and S). Two primer sets (BaAF/BaAR and BaQF/BaQR) were designed from random amplified polymorphic DNA-specific fragments for the A and Q biotypes. Four forward primers, BaBF, BaNaF, BaANF and BaSF, with a common reverse primer, L2-N-3014, for the other four biotypes of B, Nauru, An and S, respectively, were used based on their individual mitochondrial cytochrome oxidase I sequences. Six of these SCARs were useful in distinguishing each biotype from the others. Application of these SCARs will be helpful in rapidly identifying biotypes for quarantine pest control to prevent the invasion of the various biotypes. [ABSTRACT FROM AUTHOR]

In Tunisia, four major aphid species have been identified based on adult female's morphological characters:Aphis gossypiiGlover,Aphis craccivoraKoch,Myzus persicaeSluzer andMacrosiphum euphorbiaeThomas. Species identification at individual collection sites is often difficult because adults are much fewer in number than larvae which are not so easy to distinguish morphologically. We therefore set up an experiment to determine if cuticular hydrocarbon phenotypes and mitochondrial DNA haplotypes could be used to distinguish such sympatric species. Results showed that each species had an unique cuticular hydrocarbon phenotype and mitochondrial cytochromebsequence. Cytochromebrestriction fragment-length polymorphism markers, especiallyDdeI, identified in this sudy constitute a relatively simple and useful approach to distinguish the four species even at the nymphal stage. [ABSTRACT FROM AUTHOR]