Differentiation of Bemisia tabaci (Genn.) (Hom., Aleyrodidae) populations in Colombia

Abstract

We obtained evidence for genetic differentiation (detected by electrophoresis) of geographical populations of the whitefly, Bemisia tabaci (Genn.), in Colombia. The differences are undetectable by conventional taxonomic characters but are expressed at an esterase marker locus. There was no indication of host-race formation.The present data on geographic differentiation of B. tabaci in Colombia, provide support to earlier reports that B. tabaci population in different parts of the worldin particular in South Americaare biologically heterogeneous. The recent outbreaks of B. tabaci in Florida and the Caribbean, and the colonization of previously uninfested host plants, may be due to the spread of rare or new genetic variants.We have shown in the first part of this study (WOOL et al. 1993) that frequencies of electrophoretic variants at an Esterase locus in Israel are not the same in commercial, insecticide-treated fields as in samples from unsprayed sites. That result, coupled with the present data, indicates that subtle genetic variation exists in B. tabaci also in traits which are important for agriculture.

Recent Advances in Cassava Pest Management

“…ACMD is reported causing crop losses of 28-40% from all African cassava-producing countries (159,160); it has not been found in the neotropics. Until recently, the B. tabaci biotypes found in the Americas did not feed on cassava (71,180,181). It has been speculated that the absence of ACMD was related to the inability of its vector, B. tabaci, to colonize cassava.…”

Phylogenetic Relationships of World Populations of Bemisia tabaci (Gennadius) Using Ribosomal ITS1

“…It is composed of numerous populations that, while morphologically indistinguishable (Rosell et al, 1997), vary considerably in their relative ability to transmit geminiviruses Markham et al, 1994;Brown and Bird, 1995), rate of development (Wang and Tsai, 1996), ability to utilize different hosts (Burban et al, 1992;Brown and Bird, 1995;Bedford et al, 1994), and ability to induce physiological changes in some hosts (Costa and Brown, 1991;Cohen et al, 1992;Bedford et al, 1994). They also vary considerably with respect to esterase Wool et al, 1993Wool et al, , 1994Coats et al, 1994;Legg et al, 1994;Brown et al, 1995a,b;Gunning et al, 1997) and RAPD-PCR profiles (Gawel and Bartlett, 1993;De Barro and Driver, 1997;Guirao et al, 1997), and there is considerable morphological variation among their endosymbionts (Costa et al, 1995). Together, these differences have been used to characterize numerous biotypes (Bedford et al, 1992(Bedford et al, , 1993Beitia et al, 1997).…”

Characterization of Bemisia (Hom., Aleyrodidae) from the Lesser Antilles by electrophoresis

“…Other, less distinct bands can be found in both species. Some homozygous tabaci also shows one band, but this band will migrate a different distance (W OOL et al., 1994). The N biotype of B. tabaci was discovered in Puerto Rico on Jatropha and it shows no esterase bands (B ROWN et al., 1991).…”