Hosts or Prey
Aphids mostly but also other plant-sucking insects formerly called Homoptera, such as adelgids and psyllids
Identification
The adult lady beetle (ladybug or ladybird beetle) is oblong when viewed from above and dome shaped (convex) when viewed from the side. It is 1/6 to 1/5 inch (4–5 mm) long. The coloration and markings vary among individuals. The most common form in California has orange or reddish wing covers with two black spots of variable shape and a black and white pronotum. Other forms include those that are mostly black with 4 or 6 orange to red spots on the wing covers.
Eggs are football shaped and laid on end in a group. They are orange to pale yellow and about 1/25 inch (1 mm) long.
First instars are mostly blackish. Older larvae are mostly black, gray, and whitish with orange or yellow markings. Mature larvae are about 1/4 inch (6 mm) long. Pupae are cream-colored or pale when young then darken to blackish with markings of gray, pale orange, or both. They are oblong and about 1/5 inch (5 mm) long.
Life Cycle
Lady beetles develop through four life stages: egg, larva, pupa, and adult. Adult females lay eggs in a group mostly on the underside of leaves infested with aphids. The hatching larvae develop through four increasingly larger instars. Pupation occurs within the skin of the last instar glued to plant parts.
Adults live longer and lay more eggs when flower nectar and pollen are available for nourishment. When blossoms and aphids or other prey are available adults live about 2 months.
Egg to reproductive adult development time is about 3 weeks when temperatures are warm. Adalia bipunctata has at least 3 generations per year.
Habitat
Twospotted lady beetle may be native to North America. It can be found on almost any plant infested with aphids including in field and tree crops, gardens, landscapes, and wildlands. It prefers aphid-infested trees and shrubs.
To improve biological control
- Control ants because they attack lady beetles and other natural enemies.
- Grow flowering insectary plants to provide nectar and pollen to feed adult natural enemies.
- Reduce dustiness that disrupts the activities of natural enemies (e.g., periodically hose off small plants).
- Avoid the application of broad-spectrum, persistent insecticides for all pests because they are toxic to natural enemies.
See Protecting Natural Enemies and Pollinators for more information.
Species
At least 191 species of lady beetles occur in California. Adalia bipunctata is the only member of its genus reported in California. Some of its different forms of coloration and markings are pictured in Species Adalia bipunctata - Two-spotted Lady Beetle.
More Information
- Aphid Predator (Coleoptera: Coccinellidae) Adalia bipunctata Two-spot Ladybird, InfluentialPoints
- The California Beetle Database, Santa Barbara Museum of Natural History
- The Coccinellidae (Coleoptera) of America North of Mexico, Journal of the New York Entomological Society
- Species Adalia bipunctata - Two-spotted Lady Beetle, BugGuide, Iowa State University
- Two-spotted Ladybird - Adalia bipunctata, New Zealand Factsheets
Scientific classification:
- Phylum: Arthropoda
- Class: Insecta
- Order: Coleoptera
- Family: Coccinellidae
