Submitted to: Phytoparasitica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/23/2008
Publication Date: 12/9/2008
Citation: Bethke, J.A., Byrne, F.J., Hodges, G.S., McKenzie, C.L., Shatters, Jr., R.G., 2008. First report of the Q biotype of the sweetpotato whitefly Bemisia tabaci in Guatemala. Phytoparasitica. 37:61-64. Interpretive Summary: The sweetpotato whitefly, Bemisia tabaci Gennadius, is one of the most devastating pest insects of agriculture and horticulture in the world with over twenty different biotypes. The recent introduction of the more resistant biotype Q into the United States led to investigations to determine the infestation source which has centered primarily on the production of poinsettias. Poinsettias are produced from mother stock, which is often located in facilities outside the country. Cuttings from these mother plants are transferred to rooting stations within the United States, and then to nurseries for final preparation for market. Production facilities in Guatemala have been identified as one potential source of both B and Q biotype B. tabaci. An initial investigation into the original infestation of the Q biotype into the Americas indicated that the most likely origin of the insects was Guatemala. There were no reports of the Q biotype occurring in Guatemala, although the B biotype was considered a major pest on melons. To investigate the distribution of the Q biotype in Guatemala, adult whiteflies were collected from poinsettia plants in local greenhouses and from areas surrounding greenhouses including squash and bean production fields, and hibiscus. This is the first report of the Q biotype in Guatemala.
Technical Abstract: Bemisia tabaci (Gennadius) adults were collected from poinsettia plants at a commercial greenhouse, bean and zucchini vegetable fields, weed species, and wild ornamentals species in selected locations in Guatemala. Both adult and immature whiteflies were observed on infested poinsettias. Whiteflies were identified as B. tabaci using morphological characters of the pupae to distinguish them from the greenhouse whitefly, and to specific biotype using esterase isozyme patterns and mtCO1 sequencing. The Q biotype was the only biotype found on commercially grown poinsettia plants. The B biotype was observed outside greenhouse production on Lactuca spp., Hibiscus spp., and Euphorbia spp. (wild poinsettia). The A biotype was observed on wild poinsettia (Euphorbia spp.), and on field grown beans (Phaseolus spp.). More than one biotype was observed in close proximity to one another at more than one site indicating overlapping geographic populations. Further surveys will be required to determine the extent of the distribution of the Q biotype in Guatemala, especially from the agricultural production in northern Guatemala. This is the first report of the Q biotype in Guatemala.