Pest Control 101 > Treating for Bees, Wasps and other Flying insects
Bumblebees can sting!
Their stinger delivers a potent poison which can irritate most people and may cause severe allergic reactions including swelling, cramping, respiratory congestion, nausea, and temporary blindness.
Bumblebees like to nest under flat objects. They like to feel something above them and beneath them as they nest.
This leads them to make nests under boxes, under low profile decks, under rocks, under wood chips or pine straw, between the logs of a wood pile or landscape timbers, under a patio slab, under a tarp or just about any man-made or natural object which is lying on the ground that they are able to crawl under.
There are two ways to treat a Bumblebee nest.
First, if the nest is under a slab, a big rock, or a flat piece of wood; such as the floor of a deck or shed; dusting is the preferred method. This is because you will not able to spray a liquid to get them from above.
DeltaDust is perfect for this job, it is light, floats like smoke, and will penetrate to the heart of the nest. Apply it with a Crusader Hand Duster through the entrance hole the bumblebees are using.
There should be more than one hole which is active, and you can usually find them during the day by simply watching the nest.
Once the sun has set and all the bees are back in the nest, load the duster with DeltaDust and treat. Use a dust mask to protect yourself.
In most cases, they won't know what hit them. The DeltaDust will float back to where they are resting. It will kill most of them quickly and quietly.
Most will die before they can emerge. If a few come out, they will be covered in dust and too distracted or weak to present a hazard.
If you are still concerned about getting stung, you may want to have a can of Wasp Freeze nearby. This is a quick acting aerosol that will drop any stray bees immediately when sprayed.
Be sure to pump at least two full dusters when treating the nest. This insures that you have applied enough to provide a residual for the eggs, which will be hatching in the days after your treatment. By stopping the eggs, you will be preventing a recovery of the nest. It is suggested that you monitor the nest for at least four days to insure there is no new activity. If no activity is seen after seven days, the nest has been treated successfully.
The second type of Bumblebee nest is under some type of loose material like pine straw, wood chips, or a compost pile.
The best way to treat these nests is with a liquid. It will take a lot to penetrate deep enough, but in a week or two, the nest will be dead.
The best material to use for this treatment is Cypermethrin. Drench the soil with diluted Cypermethrin using a Hose End Sprayer.
It is best to treat at night. Simply hook the Hose End Sprayer up to your garden hose, add the Cypermethrin into the reservoir, set the dial to the rate shown on the bottle's label, and spray until all the material is gone. The brand name on the bottle may vary, but the active ingredient will always be Cypermethrin.
Cypermethrin is fast acting. You will be killing some bees immediately. Others will be dying during the next few days. Unfortunately, the nest may be more than a few inches down, so it may take several days to completely kill the nest. Watch the nest site for signs of Bumblebee activity.