Eight geographic strains of Aedes albopictus from Asia and North America and one North American strain of Aedes aegypti were tested for their vector competence with dengue 1 virus. Three groups of Ae. albopictus were established based on their vector competence: a) the OAHU laboratory strain, b) the three Malaysian strains, and c) the TOKYO and three North American strains. The three North American strains were similar to the strain of Ae. aegypti from Houston, Texas in their ability to transmit dengue 1 virus. A comparison of barriers to infection and transmission suggests that Ae. albopictus HOUSTON represents an introduced strain distinct from the more similar MEMPHIS and NEW ORLEANS strains. Based on these studies the North American strains were seen as more similar to a northern Asian strain (TOKYO) than to the three Malaysian (southern Asia) strains, supporting the current hypothesis that the indigenous strains of Ae. albopictus recently introduced into the United States had a northern Asian origin.