Honey Bees as Structural Pests
I have been receiving a lot of calls about bees and wasps recently. In our last newsletter, I explained why honey bees swarm and what you should do about a swarm on your property (click here for article). But what if it is more than a swarm? What if honey bees have actually established a nest on your property? The pollination services that honey bees provide are vital to our food supply, but their defensive stinging behavior can be a real problem if they’ve built a hive in your yard or even worse, within your walls or attic. If at all possible, you want to avoid killing the bees. Often a beekeeper will come and remove a hive that has established in your yard, shed, or other outdoor area. Members of the Utah Beekeepers Association (www.utahbeekeepers.com) may remove these bees for you. On their website click on the link for “Report a Swarm of Honey Bees!”
Unfortunately, it is a bigger challenge if the bees have established between the walls of your home or elsewhere within the structure. If this occurs, first you should try to contact a beekeeper to remove them. Some beekeepers will, but sometimes they are unwilling to, because removing the bees may require cutting away a portion of the wall, which can mean more work and liability than they are willing to accept. If you are unable to find a beekeeper to remove the bees, you may be forced to kill them. Many exterminators are able to do this for you, or you may attempt it yourself. Completely killing all of the bees can be challenging for many reasons in addition to the obvious safety concern. you don’t know how large the hive is within the wall. you can kill the adults, but because the pupae will survive, you may need to treat two or three times. you want to kill the queen so that she doesn’t continue to produce brood, but she could be anywhere within the hive. And lastly, not all of the bees will be in the hive when you treat it, which is another reason you may need to treat multiple times.
If you do decide to destroy the hive yourself, most importantly you need to protect yourself from both the pesticide and the bees. The pesticide label will provide guidelines, but at minimum, you should wear long sleeves, long pants, gloves, and protective eye wear. Treat at night or very early in the morning when most of the bees are present (rather than out foraging). Although any insecticide that is labeled for wasps will also be sufficient for bees, certain insecticides work better for treating wall voids. Deltamethrin is a good choice, either in its dry formulation (Deltadust) or its foam formulation (CB DFoam). you will need to make sure that the insecticide is well distributed within the hive-filled wall. If you can find the entry hole and it is above the hive, you can use this hole to administer the insecticide. However, if the entry is below the hive or if the hive is very large, you may need to inject the insecticide into the wall in one or more spots above or within the hive. Be cautious in doing this, and be very cautious about drilling into the wall in order to apply insecticide. As soon as the drill starts vibrating the wall, bees will become agitated.
Unfortunately, a bee hive in your wall presents more trouble than just the potential for stings. Once you have successfully killed the bees, you still need to remove the hive from the wall. If you do not, the wax could melt, and the wax and honey will do damage to the wall. Even if the wax doesn’t melt, do you want a lot of wax, honey, and dead bees rotting inside your wall, creating odors and attracting other insects and rodents? I have actually had people tell me that they’ve dealt with a hive within their wall by simply plugging the entrance hole. Assuming that the bees did not find another way out, this probably worked to eventually kill them, but it also left behind a lot of wax, honey, and bee corpses to decay within the wall. I would not recommend this as a solution.
-Cory Stanley, USU CAPS Coordinator