OLEAN — It hasn’t been a good summer for mosquitoes — as far as the mosquitoes have been concerned.
You may have noticed the difference between these past few months and last summer when there were a record number of complaints.
Robert Ring, director of the Environmental Health Division of the Cattaraugus County Health Department, said Tuesday there’s evidence to back up claims that mosquitoes aren’t as bad this year.
The county Health Department hired two college interns to set mosquito traps across the Allegheny River Valley to sample the number of mosquitoes at nine sites from Portville to Salamanca. A site in the town of Hinsdale is also included. Low-lying areas are the focus of the trapping.
“It’s been quiet” this summer, Ring said. There haven’t been a large number of complaints and the interns found relatively low numbers of mosquitoes in the special traps.
The interns began trapping and identifying mosquitoes in early May, Ring said. One intern has already left to return to college, while the other one will remain on the job for another two weeks. Because of that, the sampling schedule has been reduced.
Besides monitoring traps, the interns also “dipped” for mosquito larvae, an indication of things to come. The interns began dipping for larvae in mosquito breeding pools at 16 sites in late May, finding medium to high numbers of larvae at several locations.
By June 1, however, the number of larvae plunged due to a lack of rain. Soon afterward, many of the wetlands’ breeding pools had dried up, Ring said. Most are completely dry now despite some rain.
The number of larvae at the dipping sites peaked in early June at around 140 per week — from all 16 sites. Two earlier weeks showed about 100 per week each. The highest since early June was 80.
Ring said to be considered a nuisance, between 500 and 1,000 mosquitoes per trap per night is considered significant enough to consider spraying.
The county health department has concentrated on aerial spraying of larvicide for the past 20 years, meaning the spraying of insecticide last summer was unusual.
“The rain is soaking into the ground or running off,” Ring said. It is not pooling up.
“Last summer was warmer and wetter,” Ring said. “When it’s cold — in the 50s and low 60s overnight — mosquitoes are pretty lethargic.” Conversely, when it’s very hot during the day and no rain, the mosquitoes need to seek cool shade or face dehydration.
“When the mosquito population is lower, the chance of positive cases of a virus like West Nile or Eastern Equine Encephalitis is lower.
As we get into September, the temperatures will drop back a little more, meaning any mosquitoes will be less active. They are often most active after sunrise and before sunset.
In late summer last year, two cases of Eastern Equine Encephalitis in the western Cattaraugus County town of Conewango spurred aerial spraying of insecticide targeting mosquitoes over Conewango, Leon, Napoli, Coldspring and Randolph in September.
A month earlier in August, adulticide was sprayed over the towns of Allegany, Carrollton, Great Valley, Hinsdale, Olean, Portville and the cities of Olean and Salamanca due to a high number of complaints.
Because of COVID-19, the mosquito surveillance program was not conducted in 2022 or 2021.
Residents can help reduce mosquitoes on their property by denying them stagnant water to breed in.
Remove any containers that can hold water and drain pool covers and other water sources. Change water in birdbaths every few days.
