Identification of Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae) biotypes using the molecular marker, cytochrome c oxidase 1 (CO1) gene

The whitefly, Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae), is a minute polyphagous sap-sucking insect considered as one of the most economically important pests of agricultural crops primarily because of its ability to transmit plant viruses. Studies have shown that B. tabaci is a species complex composed of at least 41 biotypes that differ in their biology, host plant preference, insecticide susceptibility and ability to transmit plant pathogenic viruses. In the Philippines, B. tabaci is known as primary vector of phytoviruses of tomato, cucurbits, and cotton. However, no local study has been done in the identification of whitefly biotypes present in the country. The present study utilized the mitochondrial DNA gene, cytochrome c oxidase 1 (CO1), to identify the B. tabaci biotypes reared in the laboratory with cotton as host plant and field populations that fed on eggplant, and greenhouse populations feeding on squash and tomato. Comparison of the nucleotide sequences with those in the GenBank revealed the predominance of B biotype, one of the two most notorious biotypes of whiteflies reported. However, no sample was found identical with the other most destructive biotype, the Q biotype. Nonetheless, two other biotypes, Asia biotypes I and II 6, were found in B. tabaci samples infesting eggplant. This is the first report on the presence of these B. tabaci biotypes in the Philippines. Results showed that there is a need to assess the biotypes present in the country to design efficient management programs for the control of both the insect pest and the viral diseases it transmits. Moreover, with the formation of ASEAN Economic Community in 2015, there is a great possibility of introduction of other B. tabaci biotypes in the country from other ASEAN member states. Thus, baseline information on the local B. tabaci biotypes present in the country is necessary for biosecurity purposes.