According to the US drought monitor, every area of Massachusetts is currently being affected by drought. Moderate drought is affecting around 60 percent of the state’s land area, while another 25 percent of the state is seeing severe drought. The entirety of Bristol and Plymouth Counties, as well as the southern portions of Norfolk, Worcester and Hampden Counties are currently the driest areas of Massachusetts. Less than two weeks ago, state authorities declared every county in Massachusetts to be in a state of “level two drought,” which is a designation that calls for residents to dramatically cut back on unnecessary water usage. A drought lasting from June 2016 to May 2017 in Massachusetts was believed to have caused an increase in ant infestations, invasive beetle infestations, and Mosquito-borne disease rates in the state. Since mosquitoes are thirsty creatures that depend on free water for breeding, one would think that a drought would kill off most mosquitoes in the natural environment, but recent studies show that this is not at all the case.
A 2003 study found that mosquito populations skyrocket immediately after periods of drought in geographic regions where wetlands are extensive. This is bad news for residents of Massaccusetts where wetland marshes account for nearly 600,000 acres of the state’s total land area, and disease-carrying mosquito species rely on these natural wetlands for breeding. Researchers are able to predict the magnitude of mosquito-borne disease outbreaks by measuring the intensity of preceding droughts and the length of time in which they last. Organisms that keep mosquito populations in check by means of predation or competition have adapted to survive the seasonal drying of local wetlands. However, these organisms are unable to survive in wetland ecosystems that only become dry in response to unpredictable periods of drought, like the wetlands of New England. In other words, when droughts occur in Massachusetts, the natural predators and competitors of mosquitoes die off, which naturally causes mosquito populations to skyrocket. To make matters worse, a 2018 study found that mosquito-borne disease rates increase during periods of drought. This occurs because thirsty disease-carrying mosquitoes adapt to dry conditions by consuming blood at much greater rates in order to replace the water they lose.
Have you noticed an increase in mosquito activity around your home?