Mosquito populations surge during the summer months, as hot and humid conditions provide great breeding conditions for the insects. Their bites can be more than just an itchy menace. Some mosquitoes can transmit diseases like West Nile, malaria, and more recently, Zika Virus.
Warmer and more humid conditions, due to a changing climate, are making the season of mosquitoes longer each year. Some of the largest increases in these mosquito days have been on the East Coast and in the Upper Midwest. La Crosse, Wisconsin has an additional month each year favorable for mosquitoes compared to the 1980s. Here in the Quad Cities, we are seeing about 24 additional days of mosquitoes, compared to the 1980s.
But as we get hotter, it may actually get too hot for the bugs. Some places are getting so hot that there is actually a decrease in the number of days each year when mosquitoes can thrive. But even these places still have long mosquito seasons, meaning viruses like Zika and West Nile could spread.
As warming continues into the middle part of this century, the area favorable to mosquitoes will continue to shift and grow. A study cited by the National Climate Assessment indicated that the area in the Northeast suitable for the Asian Tiger mosquito, which is one type of mosquito that can transmit Zika, will increase between 43% and 49% by the end of the century. This mosquito already ranges as far north as New England and Minnesota.
METHODOLOGY: The formula for mosquito-suitable days is based on National Institute of Health studies incorporating temperature and humidity. This analysis examines conditions on individual days rather than multi-day heat events which can affect mosquito populations.
