Asian Lady Beetle
Commonly mistaken for the ladybug, the Asian lady beetle is a native of eastern Asia that first began sightings during the 1990s. They can be quite aggressive.
|Color||May appear in spectrum of colors from yellow to orange to red.|
|Size||About 1/3" long.|
|Appearance||Oval shape. Most have black spots with an M-shaped marking behind its head.|
They feed on aphids found in trees, crops and gardens, and therefore are considered a beneficial predator in the garden and agricultural settings.
Asian lady beetles seek out tall or prominent buildings adjacent to wooded areas in the fall, gathering on south and west sides of buildings when the sun heats exposed surfaces. Mainly a nuisance pest to homeowners, the insect becomes an irritant by attempting to overwinter in man-made structures. They enter through small cracks and crevices and will emerge when heat sources are high in the building. Even though they regularly seek shelter indoors during the colder months, Asian lady beetles will not reproduce or feed inside human habitations, despite the common fears of homeowners.
Yellow, oval eggs are deposited in batches of 20 on the underside of tree leaves, hatching after three to five days. The larval development is completed in 12-14 days and then the pupa attaches to the leaf surface. The adult emerges after five to six days, living for two to three years. There are two to three generations per year.
Although Asian lady beetles can be a nuisance when they occur in large numbers, they do not infest wood, destroy fabrics, eat human food, or damage other property. They can bite and exude a foul-smelling odor, but they do not cause damage.
Prevention & Control
The best course of action to stop Asian lady beetles from entering the home is to take preventative measures. This includes, but is not limited to:
- Sealing off all entry points to the building outdoors, including where phone lines, cable TV wires, and other pipes and vents enter buildings
- Caulking openings in the foundation and around plumbing, electrical conduits, and windows
- Repairing or replacing any damaged window or door screens, screens in roof vents and in bathroom and kitchen fans
- Covering vents
- Don't crush them! Avoid stepping on or squashing Asian lady beetles, as the insect may stain carpets, other fabrics, or walls.
- Vacuum! Simply vacuuming the insect up may prove effective.
- Prevention is the key, so caulk and close up window and door frame gaps, and any other openings into the building.
Professional Pest Control
To prevent Asian lady beetle entry, an insecticide treatment must be applied during late September or early October before the insects begin to enter buildings, in order to be effective. Once the pests have entered the building, an interior treatment can be done in winter or spring that will eliminate them as they come out of hibernation.