Multi-colored Asian Lady Beetles (MALB) are insects that were introduced to the United States starting in the early 1900s. They have been reported in a variety of areas, including the Upper Mid-West, Mid-Atlantic, and along much of the East Coast. MALB are more aggressive than our native species of Lady Bug. In some places, they have pushed the native Lady Bug out of its habitat.
MALB like to stay warm. In locations where the weather turns colder with the fall, MALB are attracted to houses that have a light-colored, warm, south- or southwest-facing side. They will then try to move towards the warmth of the indoors, which can result in a home invasion. Unlike house flies, which can be present from a few to a handful, MALB can invade houses in numbers from hundreds to thousands or more. When scared, MALB leak a stinky fluid from their leg joints. Occasionally, they bite. In addition to the nuisance factor of having hundreds or more lady bugs flying around inside the house, the homeowner is left to clean them up when the insects die.
MALB have been reported to cause a variety of allergic symptoms, including rhinitis, conjunctivitis, angioedema, asthma, and chronic cough. In the lab, allergens have been identified from the bodies of crushed beetles. Scientists were then able to then identify antibodies to MALB in patients with allergic symptoms and exposure to MALB. It appears that there is a strong correlation between the IgE antibody for a German cockroach allergen and ladybug allergen based on one study. Patients can potentially develop allergic symptoms from inhalation of MALB insect parts, from contact with the insects, or from being bitten by them.
Because MALB spend the fall and winter indoors, patients who become allergic to them can develop a seasonal allergy to an indoor allergen. In this case, their symptoms get worse in the fall and winter with MALB exposure and better later in the year (assuming they do not have other allergies). This is unusual, in that most if not all seasonal allergens develop to outdoor allergens. It emphasizes the importance of working with your allergist to make sure they have the most accurate information about the home environment possible. Currently, there is no commercial extract available for skin testing for MALB allergy, nor is there an allergy immunotherapy serum available for treatment of MALB allergy. There is, however, a commercial blood test available.
The most important measure for patients with MALB allergy to implement is environmental modifications at home to reduce their exposure to the insects. This may involve working with a contractor to minimize entry points for MALB on the exterior of the house. It may also require working with an exterminator. Otherwise, patients with MALB allergy will need to remove the insects from their homes as quickly as possible.
Patients with known or suspected MALB allergy should visit their local Allergy Partners physician for help with evaluation and management of this condition.
Dr. Nathan Hare
Allergy Partners of Lewisburg