Spreading Asian tiger mosquito

VANISHING COASTLINES may not be the only peril in a global- warming world; disease-carrying Asian tiger mosquitoes may find the hotter temperatures to their liking and may show up in places they've never been seen before, according to new research .

"Our research shows that, like many mosquitoes, this species breeds faster as the temperature gets higher," said Barry Alto, a University of Florida entomology doctoral student and co-author of the study which appeared in the Journal of Medical Entomology. "If global warming trends continue, the Asian tiger mosquito may become common in places it's not found today.

What's more, he said, the Asian tiger mosquito may be just the beginning. "Some research indicates that global climate change may alter the current distributions of other mosquito species," Alto said.

Native to East Asia, the Asian tiger mosquito has spread widely in the last two decades, transported in shipments of used automobile tires containing its eggs, Alto said. Warmer regions of North and South America, Europe and Africa now harbour the species, known scientifically as Aedes albopictus. It was first reported in the United States in 1985 and has reached at least 25 states, mainly in the East and South.

"This mosquito spreads quickly in the South," Alto said, "whereas in the Midwest, it's less common although it arrived in the mid- `80s." The Asian tiger mosquito is named for its appearance, black with silver-white bands. Though small, the species is an aggressive biter, attacking humans, livestock and wildlife, mainly during daylight hours.

Phil Lounibos, a UF entomology professor who studies the Asian tiger mosquito, said it draws interest from researchers worldwide.

"So many places are affected by this insect," Lounibos said. "It would be just a nuisance except that it can transmit serious viral diseases." In the tropics, the mosquito carries dengue fever, which infects tens of millions but is usually not fatal. A severe, hemorrhagic form of the disease infects hundreds of thousands each year and kills about 5 percent of those infected.

"Dengue is epidemic in northern and south - eastern Brazil right now," Lounibos said. "We're trying to stop it. Competition between the Asian tiger mosquito and the yellow fever mosquito, another invasive species that transmits dengue, may play a role in the crisis." Alto said the study compares reproduction of Asian tiger mosquitoes housed at 79, 75 or 72 degrees Fahrenheit. Mosquitoes kept at 79 degrees reproduced fastest, while those at 72 degrees reproduced slowest. "The difference between the low and high temperatures is 7 degrees.

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