Introduced in the West in the 1980s, the first mission of the Asian lady beetle was to biologically control the aphid population that was ravaging crops at the time, particularly maize. Over time, its reproductive rate and longevity have placed it on the list of invasive species. As with any invader, it can be a threat to homes and above all to the environment. Here are the dangers associated with the presence of Asian lady beetles, as well as some tips for avoiding them.
The Asian lady beetle, a danger to the environment
The Asian lady beetle is a common insect found in Quebec homes and even in impressive numbers, it is still harmless to humans. It can bite, but cases are rare and the insect does not transmit any disease. However, it does pose a real danger to biodiversity. It lives much longer than the ladybug species commonly found in Quebec and its larvae can attack those of other ladybugs, or even those of other insects, which can threaten their reproductive cycle.
Problems caused by Asian lady beetles in the house
When corn farmers harvest in the fall, they destroy the environment that Asian lady beetles take refuge in during the summer. These insects will then look for another place to settle. This is where their inconvenience is felt most. With the onset of winter, this species, still unaccustomed to Canada’s harsh cold, will seek refuge in homes by following the sun’s rays and sneaking through all the openings it finds. Older light-coloured houses are more at risk of being invaded by Asian lady beetles. They do not reproduce in homes and you will not be at risk of a prolonged invasion. On the other hand, they are a food reserve for rodents that decide to settle in your home. Eliminating their presence in your home could therefore help prevent, or even limit, a rodent infestation in winter.
What solutions are there against Asian lady beetles?
There is no insecticide or miracle cure for Asian lady beetles. The best thing you can do is make sure the house is well sealed and caulk any potential entry points: window frames, damaged screens and seals should be monitored and repaired if necessary. You can also set a light trap outside your home to prevent Asian lady beetles from entering.
Avoid picking them up by hand and crushing them. They secrete a messy and nauseating substance, which is still the only direct nuisance they will cause you. Instead, you should pick up Asian lady beetles with a vacuum cleaner and then empty the bag outside or in another place during the winter. Keep in mind that their controlled presence allows you to keep aphids out of your garden!
Asian lady beetles: more annoying than dangerous
You don’t have to worry about your health if Asian lady beetles invade. However, their presence can be a nuisance that can prevent you from doing trivial things: opening the door to take out the garbage can become quite a challenge! If you have any questions or need more help to deal with Asian lady beetles, please do not hesitate to contact us.