Over the past two summers, my gas fireplace exhaust box has been infiltrated by wasps. They go into the holes and it looks as though they are building their nest in side of the aluminum box. If it were any other location I would have done something about it but I am worried about using flammable solutions because of the fireplace itself. What can I do to keep them away? The Orkin guy said if you knock the nests down, they leave, but alas they have returned again this summer. Is there anything I can put on the outside of the aluminum box that will kill them or repel them? I want to be able to enjoy my deck without having the fear of being stung. It is such a hassle to have them living basically inside my house and I fear that they could eventually come into my fireplace. Thanks.
As our online WASP CONTROL ARTICLE explains, wasps like to live up under the eaves and basically any space that is both open and somewhat protected from the rain and weather. Most all fireplaces that use an exhaust pipe will have a perfect void between the square build of the siding and the actual flue which runs through the center inside the “box”. Wasps will commonly access this space from the top and once they start using it, they’ll return every year.
There are several ways you can treat the area to both control and repel the unwanted nesting. The first thing you might consider is to burn something in your fireplace. We have customers do this during the winter when wasps were found invading their home and if the nest is on the inside of the flue, this will usually knock them out immediately.
Now if the nest is located in the void of the chimney box, the “fire” treatment probably won’t help. If you see them entering a certain location over and over, you can spray either CYPERMETHRIN or INSECT REPELLENT over the entire area to keep them out. The Cypermethrin is a true pesticide in that it will kill them as they forage over the treated wood. This won’t happen immediately so you should expect to see some entering and leaving for a few days after the treatment. But eventually they should succumb to the spray over several days if you saturated the area good. The Insect Repellent is the paint additive “organic” option that you can either add to paint or stain when finishing your house to keep pests away. It can also be sprayed in the same fashion as the Cypermethrin. Though it won’t kill anything, wasps and several other invasive pests don’t like it and will stay clear of treated surfaces.
Lastly, if the fire and liquid options don’t get rid of the problem, you’ll need to dust the area with some PYGANIC or DRIONE DUST. These can be applied with a DUSTICK so you don’t have to worry about getting right up on the chimney to treat. You can also use a HAND DUSTER if this area is reachable and you’re comfortable working around the wasps. As a general rule we don’t recommend this tactic but some people are braver than others and willing to take a chance. Remember, bad things can happen when you’re up high and if you’re working on a ladder, it can be especially dangerous so be careful. The Dustick enables one to treat safely away from the nests and in most every case well worth the investment.
Here are direct links to the information and products listed above:
Wasp Control Article: http://www.wasps.net/wasp-and-hornet-control
Pyganic Dust: http://www.bugspray.com/item/pyganic_dust.html
Drione Dust: http://www.bugspray.com/catalog/products/page31.html
Hand Duster: http://www.gotosprayer.com/dusters/hand-dusters