Click to enlarge.

Beginner

Scientific Names
Multi-coloured Asian lady beetle, Harmonia axyridis (Pallas) and the seven-spotted lady beetle Coccinella septempunctata (L.)

Identification
Eggs:

• 1.2 mm in length,
• Oval,
• Bright yellow,
• Laid in clusters.

Larvae:

• 8-11 mm in length at maturity,
• Black with prominent bright yellow-orange patches,
• Covered in spines (often described as having an “alligator” shape).

Pupae:

• 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
Tight cluster through pre-harvest.

Insects Attacked
Aphids, small caterpillars, scale insects, mealybugs and mites.

Monitoring and Management
Check for lady beetles by visual examination of terminals when monitoring aphid colonies. Look for Stethorus spp. when counting mites.  If populations are sufficiently high, these predators keep indirect pests such as aphids and mites below threshold levels where IPM programs incorporating reduced-risk products are practiced.

Advanced

Scientific Names
There are several different species of lady beetles in Ontario apple orchards. Two of the most common include the multi-coloured Asian lady beetle Harmonia axyridis (Pallas) and the seven-spotted lady beetle Coccinella septempunctata (L.). Both of these lady beetles are introduced species.

Identification
Eggs: Lady beetle eggs are 1.2 mm in length, oval, bright yellow and are laid in clusters.

Larvae: Mature larvae are 8-11 mm in length and black with prominent bright yellow-orange patches that can help in distinguishing the species. Larvae are covered in spines and often described as having an “alligator” shape.

Pupae: Pupae may be dark or yellow-orange, hunched in appearance and found attached to leaves. 

Adults: Adults are broad, oval-shaped and convex in form. Adult sizes range from the very small black Stethorus spp. (1.4-1.6 mm) to the large Anatis spp. (8-10 mm). Lady beetles are often brightly coloured with spots – a warning to potential predators that they taste unpleasant.

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. Lady beetles overwinter as adults and become active in the spring laying their eggs near aphid colonies. There may be one or two generations per year in Ontario and the life cycle takes about one month. Some species, notably the multi-coloured Asian lady beetle, consume many hundred of aphids during their lifetimes. 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. Occasionally some lady beetles may feed on overripe or damaged fruits such as apples, peaches or grapes.

Period of Activity
Tight cluster through pre-harvest.

Insects Attacked
Aphids, small caterpillars, scale insects, mealybugs and mites.

Monitoring and Management
Check for lady beetles by visual examination of terminals when monitoring aphid colonies. Look for Stethorus spp. when counting mites.  If populations are sufficiently high, these predators keep indirect pests such as aphids and mites below threshold levels where IPM programs incorporating reduced-risk products are practiced.