Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: SUBTROPICAL INSECT PESTS OF VEGETABLES AND ORNAMENTAL PLANTS

Location: Subtropical Insects and Horticulture Research

Title: Population genetics of invasive Bemisia tabaci cryptic species in the United States based on microsatellite markers

Authors
item Dickey, Aaron
item Osborne, Lance -
item Shatters, Robert
item Hall, Paula -
item McKenzie, Cindy

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 7, 2013
Publication Date: June 1, 2013
Citation: Dickey, A.M., Osborne, L.S., Shatters, Jr., R.G., Hall, P., McKenzie, C.L. 2013. Population genetics of invasive Bemisia tabaci cryptic species in the United States based on microsatellite markers. Journal of Economic Entomology. 106(3):1355-1364. Available: http://dx.doi.org/10/1603/EC12512.

Interpretive Summary: The Bemisia tabaci cryptic species complex of whiteflies contains two invasive groups, MEAM1 and MED. In the U.S. group MEAM1 occurs both in outdoor plantings and in the greenhouse but group MED is only found in greenhouses. To determine the genetic structure and number of distinct populations of each species, and to estimate the origin of the MED group within the U.S., we carried out population genetic analyses on both cryptic species. Major results of the study are 1) MED contains a greater number of genetically different populations in U.S. than MEAM1 despite having been established for only a few years, 2) MED consists of two major genetic lineages, one originating in the eastern mediterranean region and one originating in the western mediterranean region, 3) both eastern and western MED are found throughout the continental U.S. and eastern MED is present in Hawaii, and 4) MEAM1 in the U.S. contains two populations from greenhouses that are genetically different from one another and from all other MEAM1 in the U.S. The results suggest that MED was introduced into the U.S. on at least three occasions and rapidly spread throughout the U.S., showing no discernable differentiation across 7,000 kilometers. The results further suggest that there is an enhanced role of greenhouses in promoting and maintaining genetic differentiation in both cryptic species.

Technical Abstract: The Bemisia tabaci cryptic species complex of whiteflies contains two species, MEAM1 and MED, that are highly invasive in supportive climates the world over. In the U.S. MEAM1 occurs both in the field and in the greenhouse but MED is only found in the greenhouse. In order to make inferences about the population structure of both species, and the origin and recent spread of MED within the U.S., 987 MEAM1 whiteflies and 340 MED whiteflies were genotyped at six and seven microsatellite loci respectively for population genetic analyses. Major results of the study are 1) MED exhibits more population structure and genetic differentiation than MEAM1, 2) nuclear microsatellite markers exhibit a high degree of concordance with mitochondrial markers recovering a major east/west phylogeographic break within MED, 3) both eastern and western MED are found throughout the continental U.S. and eastern MED is present in Hawaii, and 4) MEAM1 contains two greenhouse U.S. populations significantly differentiated from other U.S. MEAM1. The results suggest that MED was introduced into the U.S. on at least three occasions and rapidly spread throughout the U.S., showing no discernable differentiation across 7,000 kilometers. The results further suggest that there is an enhanced role of the protected agricultural environment in promoting genetic differentiation in both invasive Bemisia tabaci cryptic species.

Last Modified: 10/20/2014
Footer Content Back to Top of Page