Migration and Gene Flow Among Domestic Populations of the Chagas Insect Vector Triatoma dimidiata (Hemiptera: Reduviidae) Detected by Microsatellite Loci.
Triatoma dimidiata (Latreille, 1811) is the most abundant and significant insect vector of the parasite Trypanosoma cruzi in Central America, and particularly in Guatemala. Tr. cruzi is the causative agent of Chagas disease, and successful disease control requires understanding the geographic distribution and degree of migration of vectors such as T. dimidiata that frequently re-infest houses within months following insecticide application. The population genetic structure of T. dimidiata collected from six villages in southern Guatemala was studied to gain insight into the migration patterns of the insects in this region where populations are largely domestic. This study provided insight into the likelihood of eliminating T. dimidiata by pesticide application as has been observed in some areas for other domestic triatomines such as Triatoma infestans. Genotypes of microsatellite loci for 178 insects from six villages were found to represent five genetic clusters using a Bayesian Markov Chain Monte Carlo method. Individual clusters were found in multiple villages, with multiple clusters in the same house. Although migration occurred, there was statistically significant genetic differentiation among villages (FR T = 0.05) and high genetic differentiation among houses within villages (FSR = 0.11). Relatedness of insects within houses varied from 0 to 0.25, i.e., from unrelated to half-sibs. The results suggest that T. dimidiata in southern Guatemala moves between houses and villages often enough that recolonization is likely, implying the use of insecticides alone is not sufficient for effective control of Chagas disease in this region and more sustainable solutions are required.
Department of Biology, University of Vermont, 321 Marsh Life Science Bldg., Burlington, VT 05405. lori.stevens@uvm.edu.
Lori
L
Stevens
LENAP, Universidad de San Carlos, 12 calle 11-17 zona 2, Ciudad Nueva Guatemala, Central America.
M Carlota
MC
Monroy
LENAP, Universidad de San Carlos, 12 calle 11-17 zona 2, Ciudad Nueva Guatemala, Central America.
Antonieta Guadalupe
AG
Rodas
Department of Biology, University of Vermont, 321 Marsh Life Science Bldg., Burlington, VT 05405.
Robin M
RM
Hicks
Department of Biology, University of Vermont, 321 Marsh Life Science Bldg., Burlington, VT 05405.
David E
DE
Lucero
Department of Veterinary Medicine & Surgery, University of Missouri - Columbia, E109 Vet Med Bldg., 1600E. Rollins St., Columbia, MO 65211.
Leslie A
LA
Lyons
Department of Biological Sciences, Loyola University New Orleans, 6363 St. Charles Ave., New Orleans, LA 70118.
Patricia L
PL
Dorn
D025041:Animal Migration; D000818:Animals; D001499:Bayes Theorem; D014355:Chagas Disease / Q000635:transmission; D005260:Female; D051456:Gene Flow; D006166:Guatemala; D006801:Humans; D007303:Insect Vectors / Q000235:genetics / Q000502:physiology*; D008297:Male; D018895:Microsatellite Repeats; D014224:Triatoma / Q000235:genetics / Q000502:physiology*; D014349:Trypanosoma cruzi / Q000502:physiology
Chagas disease; Triatoma dimidiata; dispersal; genetic diversity; vector control