November 28, 2003 at 9:05 a.m.
The Asian beetle are reasonably harmless to people. They are capable of biting and breaking the skin but this is a short-lived irritation.
Fortunately, they are not known to transmit disease to people. Jeff Hahn, Assistant Extension Entomologist at the University of Minnesota writes that there is a medical problem connected to this beetle. There is a potential for some people to be hypersensitive to these lady beetles.
Some of the symptoms described in allergic lady beetle reactions include rhinitis which is a reaction that produces inflammation and fluid production in the nasal passages, sinuses, and eyelids. Another symptom is conjunctivitis affecting the eye which includes itching, tearing and swollen eyelids. It could also irritate an asthma condition.
Patients describe symptoms starting at about the same time as the appearance of the lady beetle in their homes. Allergic reactions to lady beetles can be confirmed with a positive skin prick test.
In the literature to date, there have been nine reported cases of hypersensitivity to lady beetles, although no one is certain just how many people may be allergic to them. The patients in most of these cases had a history of allergies, although in two cases allergies were not known to occur.
Most of the allergy cases described occurred in the home, but there were two instances of occurrences in the work place. Allergic reactions to the beetles are usually associated with exposure to large numbers of them, but reactions have been documented with exposure to just a small number of the beetles. Medication helped alleviate the symptoms of the reactions, but they returned when medicine was reduced. Symptoms would go away when beetles were absent from buildings.
If you suspect that you may be allergic to the multicolored Asian lady beetle, see an allergist. Then, you can be tested to confirm whether you are allergic to the beetle and prescribed medication to relieve your symptoms.
The best way alleviate an allergic reaction to the beetles is to avoid contact with the beetles. Keeping them out of your home by caulking and sealing spaces and gaps and treating the exterior with an appropriate insecticide in the fall before they start to move into your home. Once they are inside homes and walls, attics and other similar spaces, it is difficult to remove them and thereby minimize human exposure to them.
The Master Gardeners have three books for sale that make great holiday gifts. "Landscaping for Wildlife", $10.95 and "Woodworking for Wildlife", $9.95, both published by the DNR. "So Easy to Preserve", $18, published by the U of Georgia Extension Service. The 2004 Minnesota Gardening Calendar is also available for $12. Stop in the Chisago County Extension office at 38694 Tanger Drive, North Branch and take a look.