Multicolored Asian Lady Beetle (Harmonia axyridis)

John F. Baniecki, Ph.D.; M. Essam Dabaan, Ph.D.; John Freeborn, Extension Agent;
Bobby Cheves, Extension Agent; David Richmond, Extension Agent.
Nov.  2004

The U.S. Department of Agriculture made several releases of the multicolored Asian Lady beetle throughout the eastern United States in an attempt to introduce the beetle into North America as a potential biological control agent.  It took a long time for the releases made in Louisiana and Mississippi in 1979 and 1980 to become established and spread.  They are now widely established in the South, Northeast, Midwest, and as far west as Oregon.

 Description: H. axyridis occurs in many color combinations.  Adults are oval and convex, about 6 mm long and 5 mm wide.  North American populations have a mix of individuals ranging in color from pale yellow-orange to bright red-orange, with or without black spots on the wing covers.  The head, antennae, and mouthparts are generally straw-yellow, but they are sometimes tinged with black.  The pronotum is also straw-yellow and has up to five black spots or lateral spots usually joined to form two curved lines, an M-shaped mark, or a solid trapezoid.  The wing covers are generally yellow-orange in unspotted beetles.  In fully spotted beetles, each wing cover has 10 black spots.

 Damage:  Outdoors during the growing season, Asian lady beetles are quite beneficial.  As predators of aphids associated with trees, shrubs, ornamental plants, and some agricultural crops, they are reported to be better than our native lady beetles at tracking down aphids. Multicolored Asian lady beetles are not poisonous or otherwise harmful to humans, pets, or property.  They do not reproduce indoors.  However, the mere presence of such large numbers inside homes can be a major nuisance. 

This lady beetle does not carry disease, but it will bite in rare cases. Reports by Kovach (2004) indicated that biting and feeding may produce sharp, stinging pain that rapidly subsides.  Also, Multicolored Asian lady beetles have been reported to cause damage to fruit crops (both sound and previously injured fruits). Contamination of wine, which is due to the release of an orange fluid by the lady beetles when disturbed or crushed, was reported to be another potential problem.

 Life Cycle: It is believed that females overwinter unmated in protected sites, with the majority of the population mating later in the spring.  Eggs generally hatch in three to five days.  The larval stage lasts 12 to 14 days, and the pupal stage, which takes place on leaves, lasts 5 to 6 days.  In cool spring weather, development from egg to adult can take 36 days or longer.   After emergence, adults can live as long as two to three years under optimal conditions. A beetle consumes about 300 aphids before it reaches adulthood, feeding on more than 50 aphid species.

 Host Plants: Multicolored Asian lady beetles like a variety of nursery, ornamental, and field crops in North America, including cotoneaster, rose, Christmas trees, apple, pecan, alfalfa, wheat, cotton, tobacco, and small grains. They are also found in trees, such as peach, magnolia, crape myrtle, and maple.

 Cultural Control:

Multicolored Asian Lady beetles enter the house through small openings around doors, windows, and utility access points.  In addition, they can enter through siding gaps, cracks, and attic vents.  Sealing those entry points is the best method of keeping Asian Lady beetles and other pests from entering the home.  Use a high-quality silicone caulk to seal all cracks.  After the beetles have gained entry, the use of insecticides is not recommended, except for severe cases.  To remove beetles in the home, use either a broom and dust pan or a vacuum cleaner.  When using the vacuum, be sure to change the bag to prevent escape of the collected beetles.

 Control Checklist:

·         Seal windows and doors with weather stripping.
·         Prevent the beetles’ entry by caulking cracks around windows, doors, utility pipes, and siding.
·         Pay special attention to windows and lighting fixtures since the beetles are attracted to light. 
·         Install 20-mesh or finer screen over attic and exhaust vents.
·         Check attic and basement for possible entry sites.
·         Use vacuum cleaner or a broom and dustpan to pick up beetles. To avoid damaging the vacuum,
       use a sweeper attachment with a knee-high nylon hose inserted in the end.
·         If spraying for beetles inside, pick up dead beetles with vacuum cleaner. They then can be released
      outside. 
·        Seal between logs if residence is a log home.
·         Using pesticides to kill them is not suggested.
·         Be patient; the beetles will leave on their own in a few days or weeks.

 Trapping Methods:

An indoor trap, invented by USDA scientists in Georgia, uses a blacklight to capture flying insects, including the Asian lady beetle. This trap is humane and contains no insecticide, and it allows the beetles to be released outdoors in the spring. The Black Light Trap is available commercially and is very effective at night. But it is ineffective during daytime and is rather expensive ($69.95 + $6.95 S&H, or more).

 A new low-cost window trap for daytime catches of lady beetle is being developed and tested by West Virginia University researchers. Preliminary results showed that the trap was effective during daytime, when room temperature is high enough to allow enough lady beetle activity. It was also suggested that using both traps (light and window) together could reduce lady beetle population by 50%-65%. For more information, please contact your extension agent.

 A new home-made light trap also has been developed by Ohio State University, which uses items found at home or the local hardware store (e.g., clamp light, a 60-watt incandescent bulb, twist ties, transparencies or plastic report covers, 2-gallon plastic milk containers with caps, and black paint). This trap is effective and very inexpensive. For diagram and assembly instructions, please visit the Ohio State University (IPM) Website.  http://www.ag.ohio-state.edu/~ipm/lady/blt1.htm

Chemical Control (Exterior)*:

Fast-acting, residual formulations of synthetic pyrethroids (e.g., cypermethrin, cyfluthrin, lambda cyhalothrin, and deltamethrin) can be applied around eaves, attic vents, windows, doors, siding, and other likely entry points for pests.  The key is to initiate such treatments in late September or early October before the beetles enter buildings to overwinter. Once the beetles are indoors (i.e., winter or early-spring), such treatments are ineffective. These sprays serve as a chemical barrier, preventing the insects from entering, so timing and thorough coverage are essential for effective control.  The following is a list of products now labeled for use by the West Virginia Department of Agriculture as exterior treatments.  Both chemical and trade names are listed. 

 Active Ingredient:       Bifenthrin

Trade Names:               Home Defense Indoor & Outdoor Insect Killer
                                    Home Defense Indoor & Outdoor Killer 3
                                    KGRO RTU Home Pest Insect Control
                                    Ortho Home Defense Indoor & Outdoor Insect Killer

 Active Ingredient:       Deltamethrin

Trade Names:               Bonide Household Insect Control RTU
                                    Termite & Carpenter Ant RTU
                                    Clipper Spider Kill II Marine & Household Insects
                                    ZEP Commercial RTU Pest Control III
                                    Enforcer Home Pest Control XII
                                    Enforcer Ant Kill Home Pest Control
                                   Annihilator Insecticide Premise Spray

 Active Ingredient:       Cyfluthrin

Trade Names:               Bayer Advanced Lawn & Garden Multi-Insecticide
                                    Bayer Advanced Rose & Flower Insecticide
                                    Bayer Advanced Home Pest Control Indoor/Outdoor Ready
                                    Raid Yard Guard Lawn Insecticide
                                    Raid Yard Guard Ant & Roach Home Barrier
                                    Raid Yard Guard Mosquito
                                    Raid Yard Guard Wasp & Hornet Nozzle
                                    Cylence-On Insecticide

 Active Ingredient:       Tralomethrin

Trade Names:               Saga Multi-Purpose Residual Spray Insecticide
                                    Vikor Home & Yard Insect Control
                                    Rid-A-Bug Home Insect Killer
                                    Ace Home Insect Control
                                    Do It Best Home Insect Control
                                    Rid Home Insect Killer Ready to Use
                                    No-Pest Home Insect Control
                                    Agway Home Insect Control
                                    Hot Shot Rid-A-Bug Home Insect Killer
                                    Hot Shot Home Insect Control
                                    No-Pest Home Insect Control 2
                                    Real-Kill Home Insect Control 3
                                    Spectracide Ant Shield 1 and 2
                                    Spectracide Flea and Tick Killer 2
                                    Spectracide Bug Stop Indoor & Outdoor Home Insecticide
                                    Green Thumb RTU Home Insect Killer
                                    Conquer Home Insect Control
                                    KGRO Home Pest Insect Control 3
                                    Real-Kill Home Insect Control 2
                                    Real-Kill Home Insect Control 4

Active Ingredient:       Esfenvalerate

Trade Names:               Ortho Roach, Ant & Spider Killer
                                    Evercide Intermediate 2527
                                    Ortho Bug-B-Gon Multi-Purpose Insecticide Control Concentrate
                                    Concentrate Bug-B-Gon Multi-Purpose Insect Killer
                                    Yard Spray Concentrate
                                    Yard Spray
                                    Lawn Spray Concentrate
                                    Defy Yard & Kennel Spray

 Chemical Control (Interior)*: Indoor pesticide applications have limited effectiveness since  large numbers of these insects typically hide in inaccessible areas.  However, if an insecticide is used indoors, it should be limited to specific locations for relief of large and persistent lady beetle infestations.  Residual pyrethroids appear to be the most effective, but they must be applied directly to the beetles or to the surfaces they crawl over.  Different companies may market products under a variety of trade names that contain a residual pyrethroid as the active ingredient.  If you need to spray, make sure that you use an aerosol insecticide labeled for household insects, and do not forget to remove the dead beetles.

 Do not use any type of aerosol fogger or "bug bomb" in an attempt to control lady beetles.  Such chemical treatments are not warranted.  These treatments do not control the majority of lady beetles behind walls and other unseen areas.  In addition, the active ingredient in these “bug bombs” has limited effectiveness against the pests.  Overuse of these products can lead to unnecessary human exposure. These products can actually increase some indoor pest problems when scavenging pests such as ants, carpet beetles, and larder beetles move in to feed on accumulated dead insects.

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NOTE: It is important to remember that although these insects are a nuisance to humans, they are beneficial, and mechanical control is highly preferable to chemical control.  However, if chemical controls are employed on the exterior of the home, an approved pesticide must be used, and appropriate safety precautions listed on the pesticide label must be followed.  For more information, please contact your county WVU Extension Office.

 *--When using any type of pesticide, always be sure to read the label completely and follow all label directions to comply with label agreements and ensure individual safety.

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 References:

- Baniecki, John F., and Dabaan, M. Essam. 1999.  Multicolored Asian Lady Beetle

(Harmonia axyridis). West Virginia University Extension Service publication.

- Day, Eric, R. Multicolored Asian Lady Beetle in Virginia. 2001. Virginia Cooperative

Extension Publication Number 444-275.

- Jones, Susan, C., and Boggs, Joe. Multicolored Asian Lady Beetle HSE-1030-01. Ohio

State University Extension Fact Sheet. Entomology.
- Knodel, Janet J., and Hoebeke, E. Richard (1996) IPM Fact Sheet 101.00
            Cornell Cooperative Extension Service, Cornell University.
- Mahr, Susan. Know Your Friends: Multicolored Asian Beetle.@  Midwest Biological
             Control News.  University of Wisconsin-Madison.
- Ohio State University Integrated Pest Management Program. Suggested Treatment
             Methods for the Multi-Colored Asian Lady Beetle (MALB).
- Powell, Peggy K.  Asian Lady Beetles. West Virginia University Extension Service publication. 
- Shah, S., Hamrick, M., Buttler, L., and McCutcheon T. Developing Low-Cost Traps   
              for Asian Lady Beetle. West Virginia University.
- Tangley, Laura.  Ladybug, Fly Outta My Home.@  U.S News & World Report.
              January 25, 1999.