Precipitin tests and ELISA were used to investigate host-feeding patterns of 172 blood-fed Aedes albopictus (Skuse) collected at Potosi, MO, during the summers of 1989 and 1990. One hundred ten (64.0%) mosquitoes had fed on mammals, 29 (16.9%) on birds, and none on turtles or snakes. Thirty-three (19.2%) mosquitoes failed to react in all tests. Eighty-six (78.2%) of the 110 mammalian feeds were positive for lower taxa as follows: rabbit, 24.5%; deer, 14.5%; dog, 13.6%; human, 8.2%; squirrel, 7.3%; opossum, 4.5%; myomorph rodents other than Rattus, 3.6%; raccoon, 0.9%; and bovine, 0.9%. Positive feeds were not detected for the following mammals: cat (n = 99); horse (n = 95); Rattus (n = 84); and swine (n = 84). Fourteen (48.3%) of the 29 avian feeds were positive for lower taxa as follows: Passeriformes, 24.1%; Columbiformes, 17.2%; Ciconiiformes, 3.4%; and quail, 3.4%. These data, the first on host-feeding patterns for Ae. albopictus populations in the New World, indicate that Ae. albopictus is an opportunistic feeder that utilizes a wide variety of hosts and, therefore, has the potential to become involved in the transmission cycles of indigenous arboviruses.

Fourteen strains of eastern equine encephalitis (EEE) virus were isolated from Aedes albopictus mosquitoes collected in Polk County, Florida. These are the first isolations of an arbovirus of proven public health and veterinary importance from naturally infected Ae. albopictus in the United States since established populations of this introduced mosquito were first discovered in 1985. The widespread distribution of Ae. albopictus in Florida and in other areas of the United States where EEE is endemic raises concern that this species may become an epizootic and epidemic vector of EEE virus.

Ten strains of a new arbovirus belonging to the Bunyamwera group (Bunyaviridae) were recovered from field-collected Aedes albopictus mosquitoes in Potosi, Missouri. This evidence indicates that this species may serve as an arbovirus vector in the United States. The urban-suburban distribution, aggressive biting behavior, and broad viral susceptibility of Ae. albopictus may lead to the transmission of viruses of known public health importance and perhaps of viruses hitherto not transmitted to humans because of the feeding pattern of their usual vectors.

Aedes albopictus (Skuse) mosquitoes collected in Potosi, Mo., were tested for their ability to transmit a newly recognized Bunyamwera sero group virus isolated from the same mosquito population. Mosquitoes were fed artificial blood meals containing 4.5-6.2 log10 TCID50 of virus per ml. After 7-29 d at 25 degrees C, 79-99% of the mosquitoes had disseminated infections and 0-26% transmitted virus to fluid-filled capillary tubes. Transmission was first observed after 7 d of extrinsic incubation. Tests failed to detect transovarial transmission in 5,145 progeny from ovarian cycles 2-4. Following parenteral inoculation with 5.3-6.0 log10 TCID50 of virus, four of nine adult hamsters developed viremia. Ten of 16 suckling mice died following intracerebral inoculation of 5.0 log10 TCID50 of virus (fifth Vero cell passage); the average survival time was 8.8 d (SD, 3.5). No mortality occurred in 10 suckling mice inoculated with 3.6 log10 TCID50 of virus (second Vero cell passage).