The Middletown Press (Middletown, CT)
Taking a bite out of summer’s mosquito population
MILFORD — Mosquitoes are pests that we associate with lazy, warm summer evenings, announcing their presence with a highpitched whine as they hover near your ear canal.
So it might have come as a surprise to see Health Director Deepa Joseph and about a dozen other experts on Milford Conservation Trust land off of Pond Point Avenue on Wednesday — with temperatures in the 40s — looking for the bloodsucking insects.
“It’s important the we be proactive about this,” Joseph said, as she trudged into a thicket toward a vernal pool where — the cool spring notwithstanding — hibernating mosquito eggs are stirring to life. In a week or two, the aquatic mosquito larvae will be making their transition to adulthood, at which time females will be off in search of a mate and then their first blood meal.
Joseph was there to supervise the treatment of this pool with Bti, or Bacillus thuringiensis, a microorganism that releases toxins fatal to the developing larvae. As has been the case for more than a decade, City Hall has set aside money for the mosquito control effort, about $60,000 this year.
The city has a contract with All Habitat Services in Branford to treat bodies of water and to take other measures to try to stay one step ahead of the insects.
“Even though it’s been cool, the larvae are out there,” said Tanya Petruff, a mosquito coordinator with AHS. She said that thousands of possible breeding sites will be looked at over the coming weeks and months in Milford, draining them where possible. Many of these will be catch basis — about 7,500 in all — and some will be things like old tires on abandoned property and other small man-made pools.
The insects will also breed in salt marshes. Construction sites, with their water-filled tire tracks, are also appealing to the sixlegged vampires.
“Drain or dump any standing water on your property,” Joseph said.
“Don’t let the cold weather fool you,” said John J. Shepard, a scientist with the Connecticut Agricultural Experiment Station. “They will hatch based on the length of day, and not so much the temperature.”
Petruff agreed. “We’ve even found larvae under ice.” On Wednesday she sprayed the Bti pellets throughout the half-acre pool using a device that resembled a backpack leafblower.
Mayor Benjamin Blake said that Milford “is doing everything possible” to keep mosquito populations as low as possible.
Joseph said the early start will pay off later this summer with far fewer adult mosquitoes feeding on Milfordites. She also advises people to use repellants containing DEET and wearing long-sleeved shirts and trousers where possible. It’s known that human-feeding mosquitoes seem to prefer some people over others, perhaps based on their skin chemistry, the amount of carbon dioxide they exhale and other factors.
Shepard said that the Experiment Station will be setting out traps in Milford and in about 90 other towns to see what diseases the mosquitoes are carrying. Some of these use dry ice; as it sublimates, the outgassing C02 simulates a human exhaling.
There are about 50 known mosquito species in the state, although most don’t feed on humans. Some prefer birds, others like farm animals and still others seek out the family dog. Just about every vertebrate with blood in its veins has a mosquito that likes to feed on it.
Not all of these species overwinter as eggs in quiet water. With some species, the females find a snug place in a home or barn to bide their time until spring. Others like to spend the winter month in the larval stage.
Mosquitoes were around about 80 million years ago when dinosaurs ruled the Earth, and they’ve been making life miserable for animals small and large since then.
Shepard said that experts are concerned about Asian tiger mosquito, Aedes albopictus, an invasive species that’s expanding northward and is capable of spreading chikungunya, dengue fever, Zika and the West Nile virus. It’s described as an “aggressive human biter” by the Connecticut Agricultural Experiment Station.