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Multicolored
Asian Lady Bird Beetles
by
Barb Ogg, Extension Educator
Ladybird
beetles, also called ladybugs, are one of our most familiar
insects. They are important predators of aphids, scale
insect and other small soft-bodied pests of crops, garden
plants and ornamentals. Because of the beneficial nature
of these insects, scientists have introduced new species
into the U.S. to control pest insects more effectively
without using pesticides.
One
species, the multicolored Asian lady beetle was released
by USDA research scientists throughout the US in the late
70's and early 80's. It is widespread in Nebraska. This
species has also been reared and sold to gardeners by
garden supply companies.
 This
lady bug species is larger than many of our native species.
"Multicolored" refers to the tremendous color variations
in this species, ranging from black with two red spots,
to red with 19 black spots, with every combination in
between. The most common color seems to be deep orange.
The thorax of these beetles usually has black markings
on a white background in the shape of an irregular "M".
They
are a nuisance. Most lady beetle adults spend the
winter months in clusters, protected from the weather.
In its native home of Japan, Korea and other Asian countries,
the multicolored Asian lady beetle overwinters in cliffs,
but in the United States it is attracted to houses, especially
light-colored walls with a south or southwest exposure.
These 1/4" insects enter wall voids through cracks and
settle down in dark areas for the winter. On winter days
during spells of warmer weather, these beetles may become
active and you'll find them inside. These beetles cannot
live and breed in your home - they will die.
Multicolored Asian lady beetles have also been reported
to nibble, nip, or "bite" humans. They are not aggressive,
but may probe to seek moisture. They will not break the
skin or draw blood.
Control.
Because these ladybird beetles congregate in enormous
masses, the sheer numbers of these beetles can be very
frustrating for homeowners. Some of the following tips
may be helpful:
Try
to minimize entry points:
- Locate
entry points and seal cracks and crevices with caulk
to prevent entry.
- Make
sure window screens and doors are tight-fitting. Use
weather stripping.
- Concentrate
initial efforts on the south and west sides of structures.
Once
beetles are inside, the following suggestions may be helpful:
- Do
not swat or smash lady beetles. They have body fluids
that can stain draperies and wall coverings.
- Using
insecticides inside the home will not prevent other
beetles from coming inside and has limited effectiveness
unless sprayed directly on beetles.
- Vacuuming
lady beetles is as effective as insecticides and is
recommended strategy.
Exterior pesticide applications
- Ohio
State University Extension suggests that repellent insecticides
can be applied to exterior siding, including around
eaves, attic vents, roof overhangs, and doors and windows.
Pre-test a small area to ensure that the chemical treatment
does not stain or discolor siding. Wettable powder and
microencapsulated formulations seem to be most effective
against ladybird beetles. These formulations are not
readily available to the homeowner, so it may be necessary
to enlist the services of a licensed pest management
professional. Residual pyrethroids include a variety
of active ingredients, such as bifenthrin, cyfluthrin,
cypermethrin, deltamethrin, lambda-cyhalothrin, or tralomethrin.
For more information about using insecticides,
check out the following websites
- Timing
is important. If the treatment is done too early, the
insecticide will lose its effectiveness and repellency.
If insecticides are applied after the first cold snap
of fall, the lady beetles congregating indoors will
be unaffected and it may be a wasted treatment.
- Because of the expense and difficulties of an exterior
whole house treatment and the problems with timing,
this type of treatment may not be practical way of dealing
with multi-colored Asian lady beetles.
Other
Seasonal Pests - Fall
Updated
October 15, 2003
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