Things You'll Need
Instructions
Identify the hoverflies by determining the number of wings. Hoverflies have two wings; wasps and bees have four.
Introduce solitary and hoverfly parasitoid wasps into the area. The best choice is the ectemnius cavifrons, a wasp that specializes in killing hoverflies.
Starve hoverflies by removing the source of food. Remove all flowers and other pollen and nectar-bearing plants from the area because hoverflies eat and digest pollen.
Kill individual flies you encounter with the flyswatter to further reduce their numbers.