Smoking away bugs

There are biting flies on our property which are a nuisance.  Every time we go out, we spray with bug repellent which we brought from the United States.  One time when we went out to check on progress, we found brush burning near the workers.  They were trying to smoke out the bugs.  I don't think it worked very well, though, because they stopped doing it.

We are hoping this bug problem will be reduced when our fence is finished, providing a barrier between us and the neighboring corn fields.