The collection of Aedes aegypti and Ae. albopictus from Baltimore, Maryland.

In August, 1985 an infestation of. Aedes olbopictus (Skuse) was discovered in Harris County, Texas. It was the first breeding population reported in the continental USA (Sprenger and Wuithiranyagool 1986). Since 1985, Ae. albopictus has spread to 17 eastern states (Centers for Disease Control 1987) and eggs have the ability to diapause and overwinter in northern latitudes (G. B. Craig, personal communication). On the other hand, the yellow fever mosquito, Aedes oegypti (Linn.), has long resided in the Southern USA where repeated attempts have failed to eradicate it (Schlessmann 1964, 1966). Aedes azgypti is rarely found above latitude 35'N in the USA (Darsie and Ward 1981), however, breeding summer populations have been reported as far north as Rhode Island (Cookman and Lebrun 1986) and southeastern New York State (Benach and Bell 1973). In both cases, Ae. aegypti failed to overwinter and was not recovered the following season. In 1987, the Maryland Department of Agriculture conducted a survey fot Ae. albopictus from July 5 to October 1. It was learned from inquires made of U.S. Customs and the U.S. Public Health Service that tires arriving in the Port of Baltimore included shipments from Japan and Taiwan. The tires arrive in sealed containers and are unloaded at their final destination, usually a tire retreader or rubber recycling plant. This information led us to consider tire retreading operations as the major source of infestation and probable site of introduction of Ae. albopictus. Inquiries were made by telephone and in writing to businesses in Maryland that provided tire retreading services. Seven businesses were inspected for mosquito breeding, tire storage and turnover of used tires. Inspections revealed that two concerns were likely to import tires from regions or nations with endemic populations of Ae. ahopictus and to provide the necessary breeding habitat. One was Iocated in Baltimore City, while the other was located in Gaithersburg, Montgomery County. The protocol for surveillance was essentially the same as the CDC protocol (unpublished). Fifteen sites were selected at each business for