CHELMSFORD — It wasn’t too long ago when West Nile Virus and Eastern Equine Encephalitis (EEE) positive tests were spiking in the area. So to get ahead of those mosquito-carrying viruses this summer, some local towns are taking steps this week to limit those potentially-deadly diseases.
The Central Massachusetts Mosquito Control and North Fork Helicopters will be conducting helicopter applications today and Thursday, pending weather conditions, of the biological larvicide, BTI, to control mosquito larvae over selected wetlands in Chelmsford, Billerica and Boxboro.
The aerial spraying will be done between daybreak and dusk, and cover about 600 acres in both Chelmsford and Billerica, and nearly 900 acres in Boxboro.
Aerial spraying is necessary because these areas are deep swamps that cannot be reached via land, according to Richard Day, Chelmsford’s health director.
“The whole intent of the spraying program is to control the larvae population at the beginning stages of the season,” said Day, who added they’ve been spraying for more than three decades. “Eggs are now hatching, so we need to get them before they start flying and become biting mosquitoes that can carry diseases.”
Last April, pre- and post-application larval surveillance showed an 86 percent overall reduction in the emergence of spring mosquito species at treated monitoring sites, while untreated areas displayed a population decline of 20 percent.
The targeted spraying areas are dispersed all across the towns near brooks and rivers.
In addition, people who don’t like chemical sprays will be happy with BTI, according to Day; that’s because the biological agent is a natural, granular material that is only an enemy of mosquito larvae and their close relatives. It’s safe for humans and mostly all other creatures.
Follow Rick Sobey on Twitter and Tout @rsobeyLSun.
