A Comprehensive Guide to Identification, Damage, and Control
Asian lady beetles, also known as Harmonia axyridis, are a species of beetle native to Asia that have become an invasive pest in many parts of North America. These beetles are commonly found in gardens and agricultural fields, and can cause damage to plants and crops.
Identification
Asian lady beetles are similar in appearance to other lady beetles, with a rounded, domed shape and bright colors. They range in color from pale yellow to orange-red, with anywhere from 0 to 19 black spots on their wings. They also have a distinctive M-shaped mark on their heads. The adults are about 1/4 to 3/8 inch in length.
Damage
Asian lady beetles are known to feed on a wide variety of plants and crops, including fruits, vegetables, and ornamental plants. They are particularly attracted to plants that produce sap or have soft tissues, such as grapes, soybeans, and roses. The beetles feed on the sap and can cause damage to the leaves, flowers, and fruit of the plant. In severe infestations, the beetles can also feed on the bark of the plant, which can lead to stem girdling and eventual plant death.
Natural Control Methods
There are a number of natural methods for controlling Asian lady beetles in the garden. Here are a few strategies that may be effective:
Physical barriers: One way to keep Asian lady beetles out of your garden is to use physical barriers. This can include things like row covers, netting, or screens to keep the beetles from getting to your plants.
Companion planting: Some plants are known to repel Asian lady beetles, and planting them near your vulnerable crops can be a helpful deterrent. Some examples of plants that may be effective include marigolds, catnip, and garlic.
Beneficial insects: Certain insects, such as lacewings and parasitic wasps, are natural predators of Asian lady beetles. Encouraging these insects in your garden can help keep the beetle population in check.
Handpicking: If you only have a small number of beetles, you can try handpicking them off of your plants and disposing of them.
Soap and water: Spraying plants with a mixture of water and mild soap can help kill off Asian lady beetles without harming your plants.
Vacuuming: Another option is to use a vacuum to suck up the beetles. Be sure to empty the bag or canister away from your garden so the beetles don’t just crawl back out.
Conclusion
If natural pest management strategies aren’t effective, there are also a number of chemical pesticides that can be used to control Asian lady beetles. However, it’s important to use these chemicals carefully and responsibly to avoid harming beneficial insects, animals, and the environment. Always read and follow the label instructions carefully before using any pesticide.