Crews to Spray for Mosquitoes Tonight

The Montgomery County Health Department will spray parts of Plymouth Township Wednesday night for mosquitoes between the hours of 8 and 10 p.m.

Plymouth Township Manager Karen Weiss said phone calls will go out to residents regarding the spraying through the township’s emergency notification system. Weiss said the chemical being sprayed is not harmful to people, but suggested that residents go inside (along with pets) and turn off their air conditioning systems while the trucks pass  —  and for about 30 minutes after the trucks pass.

The areas affected are within the yellow section of the attached map.

Pennsylvania DEP spokeswoman Amanda Witman said in an earlier interview that the insecticide being used — Biomist 3+15 — is safe and poses “very little danger” to humans or pets because the concentration being used is so low. The spraying will be at a rate of 0.75 ounces per acre.

“In all honesty, we don’t have a recommendation that people come inside [during the spraying] because the spraying is safe,” Witman said. “It’s going to be done primarily after dark, and we anticipate that most people will already be inside.” 

Witman said the Pennsylvania DEP has never had a case of a human or a pet being affected by the spraying of Biomist; she added that the pesticide degrades quickly in the environment the following day.

Though the chemical targets mosquitoes, Witman said she couldn’t talk on whether other insects would be killed by the chemical. 

As of Aug. 13, there have been  no human cases of West Nile virus in Pennsylvania, according to the Centers for Disease Control and Prevention, however, non-human West Nile virus infections have been reported.