Jul 31, 2013 - 03:23 PM
Wasps and hornets, and anything living in a structured nest in the ground can be difficult to control just be spraying the ground. Bumblebees, hornets, etc can build large nests underground, and become a real nuisance without "digging" the nest up.
Bifenthrin (Bifen) or Talstar is a great product that can be sprayed, applied to the soil, and if possible sprayed under a deck. This pesticide will kill wasps and also repel others. It's not a fast kill, but it works and will kill the wasps if it gets to them.
Wasp Freeze, kills wasps instantly. It's an aerosol spray product and can reach wasp nests up to 15 feet away. It's a fantastic product. It's the only product I have ever used where I knew that I had the upper hand on wasps. I once dropped a wasp nest the size of a Frizbee to the ground and killed every wasp in under 30 seconds.
Dusts such as Delta Dust can be puffed under the deck, this will also kill wasps. Delta Dust is also water resistant and will give several weeks of control. You have to be able to puff it under the deck through an opening or crack.
If the nest is very large, or if you have any problems with wasp stings, then you might consider getting a bee suit. A bee suit can save a trip to the hospital.
The Waspinator is a decoy wasp nest that deters flying invading wasps. It actually works pretty well, and for the money, can provide several months of wasp control.
Hope this helps.