Florida researchers believe that climate change will make mosquitoes active in seasons other than summer. Because of climate change, the insects will be able to survive even in cold months. They expect to see this difference in areas with the most significant climate change.
Mosquitoes have varied tolerance to low temperature each season
Mosquitoes are active in tropical regions all year round. However, in winter climates, low temperatures make them go into a type of hibernation known as diapause. Scientists call these mosquitoes are cold bound as low temperatures limit their activity.
As climate changes, scientists expect winters to be warmer and shorter, while summers are longer. The longer summers and warmer winters could bring a change in behaviour for cold bound mosquitoes.
Researchers collected mosquitoes from Gainesville, Florida, during each season to study how insects are adapting to climate change. They found mosquitoes to be plastic which meant that they could tolerate different temperature ranges during other seasons.
In the spring, where nights are cold and days are warm, mosquitoes had a tolerance for a wide range of temperatures, but the range became smaller during summer when temperatures remained the same during the day and night. In the fall, tolerance stretched again.
How researchers conducted the study
For the study, researchers captured about 28,000 mosquitoes from 18 different species. They caught them using carbon dioxide emitting traps that mosquitoes naturally sought. Since animals exhale carbon dioxide when they breathe, the insects take it as a sign that food is close.
Outside of the 28,000 mosquitoes, researchers randomly selected 100 and placed them in test tubes. They then submerged the test tubes into the water. Afterwards, researchers altered the temperature and monitored when each became inactive to know their lower and upper thresholds.
It is unclear how mosquitoes make such fast adjustments to change in the weather. Some scientists suspect that evolution works quicker in smaller animals.
Researchers believe their results could help people prepare for the insect season as summer continues to lengthen. People are encouraged to get rid of stagnant water and cover any container that could hold water to limit mosquito breeding. This act will be important in reducing the disease risk carried by mosquitoes.
