Numerous types of wasps nest in environments shared with humans. While most wasps are beneficial insects that feed on dead bugs and garden pests, many also pose a hazard to people. Their stings can cause severe reactions, particularly in the very young, the very old and those with insect allergies. Some wasps, like the paper wasp, prefer to nest in enclosed areas, such as behind shutters. To keep your shutters wasp-free, you must first remove the wasps that already nest behind the shutters and then enact preventive measures to keep them from returning.
Examine the route of wasps flying in your yard during daylight hours when the insects are active. Look for a particularly heavy congregation. They will eventually lead you to the shutters where they are nesting. Do not approach them or stand between the wasps and their nest.
Fill the duster with the insecticide dust outdoors to avoid indoor contamination and to reduce inhalation. Wear a face mask or bandanna to prevent the dust from entering your nose or mouth.
Approach the shutter at night when the wasps are inside the nest and inactive. This reduces your chance of being stung and increases the likelihood of treating all the wasps in the nest. A quick peak with a flashlight may reveal the exact location of the nest, but be careful not to agitate the wasps.
Direct the nozzle of the duster into the area behind the shutter nearest the wasp's nest. Pump the dust liberally into the space. Ideally, the dust will spread out and fill the tiniest crevices as well as the nest itself. In 24 hours all the wasps should be dead.
Immediately seal the entrances to the area behind the shutter with fiberglass insulation. Do not wait and allow the wasps to leave.
Treat all unoccupied shutters in the same manner to kill any undiscovered nesting wasps and to prevent new wasps from entering. Because wasps and hornets can enter tiny areas, it may be necessary to repeat the process annually.