Bumble Bee Control
How to Kill Bumble Bees If They Become a Pest
As stated in the Bumble Bee web
page, these flying, stinging insects are usually considered beneficial and
should be left alone. In most cases, their benefits far out weigh dangers
they may present. This article addresses problems where the bees have
become a pest, usually due to the location of their nests
Chemical and non-chemical controls should both be considered.
Non-chemical control mainly consists of prevention methods. Pesticide
free control of bumble bees is discussed on the bumble
bee information page.
When the location of a bumble bee nest dictates elimination for safety's sake,
certain products, techniques and timing are essential. Using the wrong
pest control products or using any control products during the peak of bee
activity usually results in failure to control the pests and (very often) being
stung by angry bees.
First, there is timing to consider.
Stinging insects such as bees, wasps, hornets or
yellowjackets tend to be very
active in daylight hours and rest (in their nests) after sundown. If you
treat an active nest in daylight hours there are two possible bad results: you are at
much greater risk of being stung and will not kill as many bees with initial
application. Once you have located the nest, make note or mark the area so
that you can find the nesting area at dusk or in the darker hours.
During daylight hours, bees are busy foraging for all of the colony's
needs. Treating the nest during these hours will kill a few bees.
Workers returning to the nest are exposed to the treatment but the treatment
will not be as fast or as effective. Early evening treatment will catch
the majority of the workers in the nest, trapped and unable to escape safely.
Nests located beneath loose objects (mulch, grass clippings) or covered by
over-grown grass and weeds are treated differently than those that lie simply
beneath a brick, stone or other similar object.
If a bumble bee nest is located in an over-grown area, do
not use lawn mowers or other motorized grass and weed trimmer before bumble bee
nest has been neutralized!
The sound of such machinery will stir up and agitate the colony into attack
First eliminate the nest, then finish your landscaping chores. There are
two basic methods for treating bumble bee nests. Read this entire section
before deciding on methods and products needed. Most people will need only
one type of bee control; others may have such a severe problem that a
combination of these two methods might be needed.
Treating Nest Beneath Grass, Mulch
Treating Nests Beneath Rocks, Tarps, Decks
Treating nests in covered or over-grown areas is best
done by first broadcasting an insecticide over the area. This is especially
important when the entrance
hole is not visible due to loose materials. (If entrance hole is visible,
skip down to Treating Bumble Bee Nests Beneath Rocks, Decking,
The area should be fairly well drenched both on and around the suspected
entrance to the nest. Products containing Cypermethrin
work well for this job. Cypermethrin is available in both liquid and
wettable powder concentrates. Either formulation can be used; Demon
EC, Cynoff EC are professional liquid
Demon WP, Cynoff
WP are professional wettable powder concentrates.
Once you have sprayed the area (or areas), make note of bumble bee population
over the next 10 to 14 days. A repeat application might be
necessary. If you think that you are dealing with multiple nests, pushing
an insecticide dust into the entrance holes might also be necessary. This
is especially important during the time of year when there could be many bee
grubs or larvae that will soon be hatching out, producing even more worker
bees. Dusting bee colonies is discussed in the section where elimination
of underground bee nests is explained.
Besides bumble bees, any of these
products can be used for general purpose pest control in and around the home.
Liquid concentrates are more cost effective for this particular job. If
you are positive that you are dealing with only one nest, a 4 ounce bottle of
Cypermethrin concentrate may be all that you will need, especially if you have
no other pest control needs.
Pump type sprayers can be used for this type of pest control job but most people
feel safer using a hose end sprayer. A hose end sprayer will give you the
ability to treat the targeted area from a better distance and will also provide
a more thorough soaking of the nest area. When using a hose end sprayer,
liquid concentrate insecticides work better than wettable powder concentrates.
The type and amount of loose
materials covering the entrance to the nest will dictate the amount of spray
needed. If cover is heavy, more than one application is often called for.
There are three different sizes of liquid concentrate Cypermethrin: 4 ounce, 16
ounce, 32 ounce. If you do not intend on doing your own general household
pest control, you will usually not need the larger containers. Only when
there is a great deal of landscape area to deal with will you need larger
volumes of liquid insecticides. In this case, Demon
Max (Demon EC) is your best bet. For smaller jobs, buy one or two 4
ounce bottles of Cypermethrin.
Keep pets and children off of any treated area until area has been allowed to
thoroughly dry. Once dry, the area will be safe for re-entry - unless
bumble bees are still noted flying in the area. Bumble bees do not always
die as quickly as we would like; they are tough and stubborn.
Treating Nests Beneath Rocks, Tarps,
Choosing Pest Products
Application of Pest Products
When the entrance to bumble bee nest is easy to locate and is not covered with tall grass or
mulch, the best control method is dusting. A professional grade
insecticide dust is formulated with tiny particles that will float through
targeted area, almost floating like smoke. When properly applied into the nest
entrance hole with a good hand bellows duster, the dust will travel deep into
Choosing Pest Products
There are two different dusts that will work: Drione Dust and
The advantage of Drione Dust is that it has a very fast knock-down or kill of
targeted pests. Delta Dust has the advantage of being water-proof, an
asset that is very attractive when treating soil that might contain any type of
moisture. Delta Dust is the most popular of the two insecticides.
Pest control technicians who have more products at their disposal have reported
great results when combing the two dusts for a single application. This
combination gives them a quick knock-down of existing bees and fewer call-backs
when young bees can emerge.
Apply your insecticide dust with a hand bellows duster. There are two good
hand bellows dusters to choose from: 360 DustWand and
Crusader Duster. Either of these
dusters will due a good job. The advantage of the Dust Wand is that the
extensions provide a longer reach.
Application of Pest Products
When applying pesticide dusts into cracks, crevices or entry points,
proper filling of the dusting device is of utmost importance. When a hand
bellows duster is completely filled to its capacity or when dust is packed down
inside the duster, dust does not come out in proper form. Never over fill
a hand bellows type insecticide duster. Fill duster 1/2 to 2/3 from
top. After replacing the fill opening, gently shake the duster just prior
to application. The small area inside the duster (created by NOT
over-filling the duster) creates a space that is sorely needed. When the
duster is shaken, a small "cloud" of insecticide dust is formed in the
By gently shaking a properly filled duster, the dust particles will exit
the duster nozzle in a thin, smoke-like cloud as the hand bellows duster is
squeezed. This thin cloud of duster
will travel further through the targeted area (in this case, an underground
bumble bee nest), reaching far more adults, eggs and larvae. The next
effect of proper application is over-all coverage.
If large amounts of
Delta Dust or Drione Dust
are merely "dumped" into
the nest entrance, the majority of the dust will merely pile up in one
place. Properly applied dust will "float" through the chambers
and most of the particles will tend to stick to top, bottom and sides of the
tunnel as well as the nest itself.
Treatment of a bumble bee nest involves coating the nest entrance, nest, eggs,
grubs and adults. For most nests, you will need to apply two applications:
partially fill your duster, shake thoroughly, empty contents into nest;
repeat. This double application will assure better control over all stages
of the bee and will contaminate the nest and void, which will kill bees
returning to the nest area.
As mentioned previously, the best time to kill bumble bees is when they are at
rest or as they sleep. Avoid treatment during daylight hours; treat the
bumble bee nest at dusk or when it is dark enough for the bees to cease their
activity but just light enough for you to see what you are doing.
You can (using a flashlight) kill bees at night but there are a couple of
possible hazards that you might run into: stumbling over unseen objects
and actually attracting angry bees. The first possible hazard listed is
mainly common sense. If you trip and fall over any unseen object in the
area, you not only risk possible harm from the fall but also risk waking up the
resting bees. Using a flashlight to navigate to the sight or while
treating the nest can be a problem.
If the bees are disturbed and exist the nest, they could very well be attracted
to light emitted from your flashlight. (If light is needed, try setting
your flashlight in one area before you approach the nest from another area.)
Bee Picture with Carpenter Bee
Bumble Bee Credits
Crusader Duster Drione
Dust Delta Dust
Pest Control Site Map Pest
Control Pests Carpenter
Bee Control Bumble Bees