Reducing Pesticide Drift

Editor’s note: The following article, which discusses how PMPs reduce pesticide drift, originally ran in the Targeting Mosquitoes e-news sponsored by MGK. Other articles from that e-blast can be downloaded here.

Much can go wrong when the pesticide you apply for mosquito control drifts into a neighboring yard with honeybees, a koi pond or homeowners who disapprove of pesticide use in general.

And while pesticide drift is a bigger concern in some parts of the country than others, it can cause problems in any community. As such, all pest management professionals should take steps to reduce it.

In California where “it’s a huge issue,” Clark Pest Control recently launched a mosquito control program that aims to reduce drift, said Darren Van Steenwyck, the company’s director of learning and training.

“Legally, we are not allowed to apply pesticide as a private entity on somebody’s yard without their consent,” he said. If material drifts into a neighbor’s yard, then technically an application has been made without consent and without the required documentation and notification. That can result in fines and major social media fallout.

Pest management professionals shared how to reduce chemical trespass:

1. Embrace IPM.

“We have to view mosquito control truly as integrated pest management and not focus just on the adulticiding,” said Van Steenwyck.

That means conducting a thorough inspection of the property to find mosquito breeding and resting sites, applying larvicide to areas of standing water (bird baths, neglected fountains), and installing and servicing mosquito traps, which draw the pests away from patio, decks, pools and playsets.

The final step is applying a combination adulticide and insect growth regulator. This combination knocks down the existing adult mosquito population while interrupting the pest’s life cycle so future adult mosquitoes don’t emerge.

2. Change application equipment as needed.

While inspecting the property, consider the type of application equipment best suited for the site. The standard pest control industry go-to for mosquito control is a backpack mister blower, which creates super fine droplets that provide excellent coverage but also may drift to other properties in more tightly spaced neighborhoods. “We can’t control where it goes,” Van Steenwyck said of the mist generated by these machines.

One strategy to manage this is to keep your back to the property line, treating toward the house instead of away from it.

“That will work in some circumstances but not all,” said Van Steenwyck. This is because trees and shrubs growing along a property line often harbor mosquitoes and need treatment. These situations call for a “more controlled” application approach, such as using a battery- powered backpack sprayer, which creates larger droplets that are less likely to drift.

A backpack sprayer, said Van Steenwyck, is best to use in small yards in dense neighborhoods; a mister blower is better suited for homes spaced further apart on more land.

3. Monitor windspeed.

Some mosquito control products cannot be applied by mister blower if sustained windspeed exceeds a specific mile per hour, per the label. That’s why service technicians at ABC Home & Commercial Services in Austin, Texas, carry pocket-sized anemometers or wind meters, said Brian Kelly, general manager of company’s pest control division.

Technicians take several readings while on property and document the average windspeed on the invoice. If it is too windy, they may switch product or application method; or reschedule service.