Unusually High Temperatures in Sierra Nevada Lead to Surge in Mosquito Population
The Sierra Nevada region is currently experiencing an unexpected surge in the mosquito population, just in time for the peak summer tourist season. The area is witnessing an explosion of snowmelt mosquitoes, a group of highly aggressive species that hibernate beneath the ice and emerge to feed as it melts. However, this year’s boom is happening later than usual due to the record-breaking snowfall in the spring and the late start to the snow melt.
Typically, these mosquitoes emerge gradually throughout the spring and early summer, but the sudden temperature change this year has disrupted their usual pattern, according to Joel Buettner, manager of the Placer Mosquito & Vector Control District. He explained, “Because all the snow started to melt at once, we had a very delayed start to the season.”
The surge in mosquitoes may pose challenges for individuals visiting the area for summer activities, particularly along the Pacific Crest Trail, where patches of snow and standing water still exist. Buettner highlighted that snowmelt mosquitoes have a shorter life span than other species, which drives them to exhibit more aggressive host-seeking behavior. He added, “When they emerge as adults, they are looking for a blood meal to lay eggs again, and they prefer mammals like humans as opposed to species that prefer birds and other wildlife.”
Fortunately, the snowmelt mosquitoes do not carry the West Nile Virus, which was detected closer to Sacramento in June. Additionally, these aggressive mosquitoes have already vanished from areas where the snow has completely melted, such as the North Lake Tahoe region. Buettner assured that his office is remaining vigilant for emerging threats, especially after the confirmation of the first domestic malaria cases in Texas and Florida last month, which he described as “very concerning.”
While there are species of mosquitoes capable of carrying malaria in the Central Valley, California officials have yet to report any cases. Buettner assured, “We’re doing our best to minimize their contact with people. At this point, we don’t have any active concern in California.”
To prevent mosquito bites, officials recommend individuals wear approved repellent and protective clothing. They also recommend eliminating all standing water around homes, as mosquitoes breed in stagnant water.
Mosquitoes, classified as the deadliest creatures on earth by the World Health Organization, serve as vectors for diseases including chikungunya, dengue, and Zika. These diseases can be transmitted with a single bite, leading to the deaths of an estimated 700,000 people worldwide every year. Last week, Kern County officials recorded the first human case of the St. Louis encephalitis virus, which in rare cases can prove fatal and is also spread by mosquitoes.
Brynn Carrigan, director of Kern County Public Health, stated, “This first confirmation of a mosquito-borne illness in a Kern County resident should serve as a serious reminder that we all need to protect ourselves against mosquitoes.”
Individuals are urged to take precautions to protect themselves from mosquito bites and minimize the risk of mosquito-borne illnesses.