Key Features
- Round, black or orange-red body
- Varied number of spots
- Spiney or wax-coated larvae
Symptoms
Lady beetles vary in color and shape. The few species many people are familiar with are round and spotted. However, some species are smaller and black and others are more elongated (convergent lady beetle and pink spotted lady beetle). The larvae are dark blue with orange bands and are very spiny. Both stages are predators of many pests including aphids, whiteflies, scale insects, thrips, and mites.
Biology
There are many species of lady beetles and their biology varies between them. The most commonly seen lady beetle in the Midwest is the Asian lady beetle which was introduced from Asia and established itself as the dominant lady beetle in these states. They can be distinguished from other lady beetles by the black "W" or "M" behind their head. Asian lady beetles lay eggs in the spring which hatch into an alligator-like immature stage (larvae) that feed on many soft bodied pests. These larvae are excellent predators and can consume many aphids and other pests during development. After a few weeks, the adult activity is seen after a pupation period. Adults consume many soft-bodied pests throughout the summer. Around fall, adults begin seeking an overwintering area such as corners and cracks inside buildings and homes.
Management Recommendations
Lady beetles feed on insect eggs, soft bodied insects such as aphids, mites, scales and young caterpillars. They should not be killed in outdoor settings. However, when Asian lady beetles become a nuisance as they attempt to overwinter inside homes and buildings, certain control measures can be taken. Vacuuming the beetles and emptying the bag outdoors away from the structure is an effective way to get rid of the beetles. Asian lady beetles should not be squashed as they bleed a foul smelling fluid when they are disturbed. This odorous liquid is capable of staining walls and furniture. Caulk your windows and doors to prevent entry of these nuisance pests into your home. Perimeter sprays of insecticides can be applied around the foundation of the home to prevent entry of these insects into the structure (see entry under centipedes for list). Consider hiring a pest control professional to apply the products. DO NOT APPLY pesticides that are labeled to apply to your home (e.g. Ortho Home Defense) on plants. These materials are formulated to stick to structures and may burn your plants.
Effective Pesticides
Pesticides are neither available nor recommended for managing this pest.
Resources
- Not satisfied with ID? Contact the Purdue Plant and Pest Diagnostic Lab
- Sign Up for the Purdue Landscape Report
