Collections of Jamaican whiteflies were identified using morphological characters. Those identified as Bemisia tabaci (Gennadius) were further identified to esterase type using diagnostic general esterase patterns using native polyacrylamide gel electrophoresis (PAGE). Over 216 B. tabaci adults from 22 Jamaican collections were identical to the B type esterase banding patterns identified first for the B biotype from Arizona, U.S.A. Of the plant species sampled in Jamaica, 86% were hosts of the B biotype of B. tabaci. Non-B esterase patterns were identified for two B. tabaci colonizing cassava and milkweed, respectively. Maximum likelihood and parsimony analyses of the mitochondrial (mt) 16S ribosomal ribonucleic acid (rRNA) sequences for Jamaican B. tabaci and reference sequences for well-studied B. tabaci haplotypes indicated that the non-B B. tabaci from Jamaica were of New World origin, whereas individuals identified as the B biotype were indistinguishable from those for other B biotype collections, worldwide. Bemisia tabaci collected from cassava in Jamaica was most closely related to the monophagous Jatropha biotype described in Puerto Rico, U.S.A., at 98.2% nucleotide identity. The collection from milkweed shared 98.4-99.6% nucleotide identity with several polyphagous haplotypes in the Americas and Caribbean region. The mt 16S rRNA sequence for the B biotype from tomato and muskmelon in Jamaica shared 99.1-99.3% nucleotide identity with the B biotype reference from Arizona. The presence of two New World haplotypes of B. tabaci in Jamaica are being reported for the first time, which may be analogous to the Jatropha and Sida biotypes (races), respectively, previously known only from Puerto Rico, and confirm that the exotic B biotype of B. tabaci is widespread in Jamaica.