BIOTYPE DETERMINATION OF SPANISH POPULATIONS OF BEMISIA-TABACI (HEMIPTERA, ALEYRODIDAE)

A survey was made to assess the biotype status of populations of the w hitefly Bemisia tabaci (Gennadius) in Spain. The study involved observ ation of the squash silver leaf reaction, analysis of esterase pattern s and application of a RAPD-PCR technique. The results obtained by the three methods were fully consistent and showed that the Spanish popul ations of B. tabaci were composed of two genetic types. One correspond ed to populations of the B biotype, found in Tenerife (Canary Islands) , Barcelona, Madrid, Malaga and Almeria. The other, showing a unique R APD and esterase pattern, was found in Majorca (Balearic Islands), Sev ille, Valencia, Murcia and Almeria, as well as in the Algarve Region o f Portugal. RAPD patterns of other populations from the rest of the wo rld used for comparison showed that populations from Arizona (USA), Is rael, France, Denmark, Italy, Netherlands and Japan have similar RAPD patterns typical of the B biotype. By contrast, populations from the I berian Peninsula, Turkey, India, Pakistan and Arizona (A biotype), sho wed different and unique patterns.