Mosquitoes are tiny insects less than half an inch long, yet they are responsible for the deaths of almost three-quarters of a million people each year, Mason Crouthamel said.
Crouthamel is coordinator of the Berks County Conservation District’s mosquito-borne disease control program.
“The mosquito is actually the world’s deadliest animal,” he told City Council during a recent report on the conservation district’s efforts to monitor and control mosquito populations in Reading and Berks.
Mosquitos can spread deadly viruses and other diseases to humans and other animals. That is why the conservation district uses a local- and county-level approach to target the blood sucking insects and their larva through an integrated mosquito management program that also tracks West Nile virus activity.
This year’s program will start next month.
“Our main program conducts larval and adult surveillance and control throughout the city and throughout the county,” Crouthamel said.
Mosquito larva and adult insects are trapped and tested for different diseases and viruses, he said.
Over 60 species of mosquitoes can be found in Pennsylvania, according to the Penn State Extension.
Of those found in Berks, the Asian tiger mosquito poses the greatest problem in the city, Crouthamel said.
The adults of this introduced species can be recognized by their black bodies with white stripes and are known vector for West Nile virus.
That means they can carry and transmit the disease.
Understanding mosquito biology is essential for controlling mosquito populations, he said, providing a brief overview of the insect’s four-stage lifecycle.
The egg, larval and pupal stages are found in water habitats and do not breathe air or eat until they become adults.
Treatment, surveillance
The goal is to reduce habitat by preventing water from collecting in old tires, buckets, flowerpots and other items.
Crouthamel and another technician teamed with the city’s Public Works Department last year to clean up areas where debris provided a mosquito breeding ground. They also did a sweep of residential neighborhoods to help reduce larval habitat and educate residents.
“We look for abandoned pools or tarps or tires or just trash of that nature that may hold water for periods of time,” he said.
Treatments and surveillance operations also are conducted in catch basins. The basins can become a problem if not draining properly or when filled with debris.
“Thankfully, we’ve spoken with the public works crew and they do a very nice job of cleaning, keeping the catch basins free of debris for us,” he said.
The team also trapped and tested more than 10,000 adult mosquitoes for West Nile virus last summer.
“We had 22 positive mosquito samples in the city and our first was on August 10,” Crouthamel said.
The low number of positives was surprising.
“This was pretty shocking to us,” he said.
Usually, the first positive of the year comes from somewhere in the city, he noted, but it is generally earlier in the summer.
Crouthamel credited the partnership with the city for the good outcome.
“Through the help of city officials and through our increased larval surveillance and partnerships, we were really able to knock that back last year and had a much later start to our positive season in the city,” he said.
Mosquitoes only lay their eggs in standing water, so moving water, such as that in streams or rivers, is not a problem, Crouthamel said in answer to a question from Councilman O. Christopher Miller.
Many of the fish, frogs and even dragonflies and damselflies will eat mosquito larvae in ponds, Crouthamel said.
“So they’re great natural control method for us,” he said. “In terms of the City Park pond, I know there’s a lot of fish in there. There’s a lot of turtles in there. So they do a really great job of controlling the mosquito populations there.”
Residents’ actions
Residents can help by removing outdoor items that can collect water, such as stored vehicles and watercraft, tarps and tires.
To protect oneself from mosquito bites and infection risk wear long-sleeved shirts and long pants during peak mosquito hours from dusk to dawn, Crouthamel said.
Sprays and other repellents can be applied to the skin or clothes as indicated by the product instructions.
“You can use a fan to try to blow the mosquitoes away from you if you need to, especially on those hot days throughout the summer,” he said. “Ultimately, it’s whatever works best for you.”
