Lady Beetles
Coccinellidae
Scientific Names
Multi-coloured Asian lady beetle, Harmonia axyridis (Pallas) and the seven-spotted lady beetle Coccinella septempunctata (L.)
Lady beetles are considered beneficial insects in grapes until harvest. Multi-coloured Asian lady beetles (MALB) aggregate on the injured berry clusters at harvest and when disturbed or crushed release chemicals that causes a taint in the wine.
Identification
Eggs:
- 1.2 mm in length,
- Oval,
- Bright yellow,
- Laid in clusters.
- 8-11 mm in length at maturity,
- Black with prominent bright yellow-orange patches,
- Covered in spines (often described as having an “alligator” shape).
- Dark or yellow-orange,
- Hunched in appearance,
- Found attached to leaves.
Adults:
- Broad, oval-shaped and convex in form,
- Sizes range from 1.4-10 mm,
- Often brightly coloured with spots.
Often Confused With
- Lacewing larvae – lady beetle larvae are sometimes with confused with lacewing larvae due to their over all body shape, but lack the prominent sickle-shaped mouthparts.
Lady beetle adults are distinct and not readily confused with other insects. There are many different types of lady beetles, and it can be difficult to distinguish between the different species. Ladybug larvae and pupae are frequently seen in orchards, but often not recognized.
Interaction With Host
Adults and larvae are efficient predators. They are found in a variety of crops and other plants in the landscape. While some are generalists – feeding on aphids, small caterpillars, scale insects, mealybugs and mites – others such as Stethorus spp. feed almost exclusively on phytophagous mites. The number of prey killed is affected by pest density. In situations where prey is abundant, lady beetles may only partially consume their prey before moving on to the next.
Period of Activity
Bud break through veriason.
Insects Attacked
Aphids, small caterpillars, scale insects, mealybugs and mites.
Monitoring and Management
Check for lady beetles by visual examination of shoots when monitoring. Look for Stethorus spp. when scouting for mites. If populations are sufficiently high, these predators keep mites below threshold levels where IPM programs incorporating reduced-risk products are practiced.
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