It’s mid summer and you are enjoying the warm weather on your back deck. You notice an impressive number of wasps lingering around the deck railings on the sunny side of your home. You are alarmed and assume that there must be a wasp nest that needs your attention in the area. After a cautious inspection of the area you turn up nothing. So what the heck is going on here?
This is a scenario that we are faced with every season. What you are observing is likely wasps foraging for nesting material. Most people don’t realize that wasp nests are made of wood pulp that they have gathered from the surrounding environment.
In the wild, this foraging happens on trees and woody plant material. In a residential neighborhood however, often the best wood resource often is weathered wood of decks, sheds, swing sets and fence lines. This brings wasps into close contact with people and causes all kinds of anxiety. In most circumstances wasps engaged in this activity are not highly aggressive and pose little real threat.
What can I do to prevent this?
The best option is to seal the exposed wood with heavy exterior paint. Wasps prefer to utilize weathered and unprotected wood, covering this wood with paint or equivalent sealants will significantly reduce the availability of this resource. This is almost always our first recommendation.
The second option, though not ideal, is to treat the wood surfaces with a highly repellant pesticide. This can be effective for wood surfaces where sealing/painting is not possible or practical. This type of pesticide application will provide relief temporarily but may require re treatments to maintain its efficacy. If you attempt this treatment protocol yourself, as always – READ THE PESTICIDE LABEL, IT’S THE LAW! There are no “safe” or “non-toxic” pesticides.