Mosquito season gets longer in U.S.: Washington Post

NEW YORK, Aug. 22 (Xinhua) — As global temperatures rise due to climate change, mosquito season has lengthened across much of the contiguous United States, a development that scientists warn could heighten the risk of outbreaks of diseases such as dengue and malaria, and the spread of West Nile and Zika viruses, reported The Washington Post (WP) on Thursday.
“Over the past four decades, more than two-thirds of the country has seen an increase in ‘mosquito days’ – defined as days with an average humidity of at least 42 percent and temperatures between 50 and 95 degrees Fahrenheit (10 and 35 degrees Celsius),” said the report.
The Northeast, which has warmed faster than the rest of the country, experienced the biggest increase in mosquito days. In Vermont, for instance, the past five years have averaged 17 more mosquito days compared with the period from 1980 to 2009.
Mosquito season shortened in hotter regions such as Texas, which experienced more frequent temperatures exceeding 95 degrees, pushing mosquitoes past their physiological limits. The growing prevalence of droughts in the southwest has led to fewer days with sufficient humidity for mosquitoes to thrive, according to the report.
Good mosquito data is hard to find. While some state and local agencies monitor mosquito populations, there is no comprehensive national database. Instead, scientists use weather data to map when and where mosquitoes are likely to thrive. ■