If your certain
there is no ground nest around the shrubery then you shouldn't have much of a problem mowing around it. They shouldn't bother you that much as they are not there in defense of a nest. Like mowing clover with honey bees on them. Most bees will only sting if they feel their nest is being threatened. If you find a hole in the ground where their entrance is, at dusk (and not before) pour about a pint of gasoline in the entrance hole. The fumes will smother them in the nest. No need to set afire except for the pure injoyment of it. Be mindfull of hornets in the shrubery. They love to build their nest in them. A hornets sting is doublely worse than any other bee sting. Their nest are the characteristic gray ball hanging from a branch or rafter or under an eve somewhere.