Expect problem to get worse with higher temperatures, changing precipitation patterns and rising sea level
CAPE MAY COURT HOUSE — When summer comes around, mosquito bites become a daily occurrence and their escalating numbers a problem.
With temperatures increasing and precipitation patterns changing, the issues appear likely to worsen.
Every county in New Jersey has a department whose sole responsibility is to monitor and maintain mosquito populations and viruses.
The Cape May County Department of Mosquito Control stays on top of the changing number of species and what viruses they carry.
“Think of us as a surveillance operation,” said Mathew Diem, the department’s assistant superintendent. “We’re constantly looking for mosquitoes in their larval habitat before they emerge and start flying around biting people.”
The department follows Integrative Pest Management (IPM) regimens to stay on top of what viruses are transmitted.
Geography affects the number of mosquito species found in an area. While some counties are inland, Cape May is a peninsula bordered by water on three sides.
“They’re definitely one of the worst,” Diem said, referring to the county’s mosquito problem. “Any of the counties that have an area of salt marsh and either the ocean or the bay have problems. In our case, we have both.”
The county’s landscape lends itself to a large mosquito population.
“Our topographical and geographical location is unique because we’re a peninsula,” Assistant Administrator Ron Simone said. “This differentiates us from the rest of the state, which makes our mosquito habitat unique and more widespread than other counties across the state.”
One of the department’s top concerns is what viruses the mosquitos are spreading.
“A spectrum of mosquitoes can carry multiple viruses while some mosquitoes are not known to carry or transmit any,” Diem said. “We have 47 mosquito species in this county and, of those, there’s a small handful that are going to transmit a virus.”
Over the past decade, viruses have fluctuated as different species became more prevalent.
Precipitation is one environmental factor that affects the number of species. Climate change not only refers to shifts in temperature but precipitation as well. As temperatures vary, seasons will experience unprecedented amounts of rain.
More frequent rain will play a role in mosquito populations.
“More water, whether it be sea level rise or water coming from coastal storms, will increase mosquito production,” Simone said.
Bodies of water provide large habitats for mosquito reproduction.
“I would say that what we’re noticing is more like a shift in species,” Diem said. “So as the water seems to rise, those areas on the salt marsh are the first to be impacted.”
A shift in species will ultimately result in different viruses emerging, which is why the department is constantly monitoring species variability.
“People talk about the variability with rainfall a lot,” Diem said. “The highs and lows have increased and that’s something that I hear mentioned at the state climatology level.”
Diem explained that this past March was recorded as the rainiest since 1995.
Rain becomes a problem because it turns dry landscapes into wet ones.
“It’s when things dry down completely and they’re barren and then fill up again,” Diem said. “That’s perfect mosquito habitat, and you definitely see more of that when the weather’s more variable.”
According to Diem and Simone, population levels have stayed constant over the past decade and do not seem to be changing rapidly. Both were unsure about climate change’s overall effect on mosquitos but recognized the effect different temperatures and precipitations have had and will continue to have.
“The main ones that we’re focusing on as far as our virus vectors, and the ones that we trap and test, those have been pretty consistent,” Diem said. “It’s probably going to be continually changing where we’ll always be packing on a few new species here and there.”
The department alters its regimens to control these spreads and is tasked with creating treatment plans.
“In the past year, two years, there are products that came on the market that are labeled as organic and are used as barrier sprays,” Diem said. “You can treat an area with a repellent effect, so you don’t have to kill everything in the air.”
Both men explained that their main goal is to be as least invasive as possible. Instead of chemicals, the barrier sprays use natural oils. “The main ingredients are a kind of mint and clove,” Diem said. “Mosquitoes hate anything with spearmint. Peppermint is a big deterrent to mosquitoes.” The department prioritizes the county’s safety. Its strategies not only aim to maintain virus spread but to preserve the county’s natural landscapes.
“Sometimes mosquito control gets a bad rap because we’re very visual, like you think of trucks spraying neighborhoods and helicopters spraying over fields,” Simone said. “We spray ounces, and sometimes, the typical flow rate for something we’re putting out is half an ounce in an entire acre.”
– By JULIA DiGERONIMO/For the Sentinel