Figure 1. European paper wasps on a shutter. Their nest is between the siding and the shutter. Photo by Amanda Bachmann.
Wasps receive attention no matter the time of year, but they are especially noticeable in late summer and early fall. Wasps such as yellow jackets and paper wasps have annual nests, so the majority of the individuals that are active now will not survive the winter. Only the newly produced queens will find a sheltered location to overwinter and begin a new colony in the spring.
Many annual wasp nests escape detection for most of the season. These nests are small and often hidden. Since the colonies are at or close to their maximum size by late summer, the nesting areas become more apparent. Soffits, eaves, shutters, and other voids on the exterior of a home or garage are the preferred places for wasps to build their nests (Figure 1).
At this point in the year, attempting to control annual wasps is mostly unnecessary. After the first one or two hard frosts, the colony will die. The best time to control a wasp nest is in the spring when their activity is first noticed. Never seal up a void or opening that contains live wasps or an active nest, as they may chew their way out and end up inside the affected structure. Wasp control should be attempted only with great care and preparation. If applying an insecticide, choose a time with cooler temperatures as the wasps will be more sluggish.
Not every wasp nest has to be controlled. Wasps are considered beneficial insects. They hunt or scavenge for caterpillars and other insects to feed to their young (Figure 2). If they are nesting in an out of the way location, consider allowing them to stay as they can provide pest control for the garden.
Figure 2. Wasps feeding on insect remains in a car grill. Photo by Amanda Bachmann.