Ladybird beetles
Variable ladybird adults
© R. Broadley, Queensland Government
Minute two-spotted ladybird adults and larva
© D. Ironside, Queensland Government
A raft of ladybird eggs
© D. Ironside, Queensland Government
Common spotted ladybird adults and larva
© D. Ironside, Queensland Government
Adults and larvae of ladybirds are important predatory insects in most crops, especially early season and when chemicals have not been used against pests. Ladybirds, along with lacewings and hover flies, prevent explosive increases in aphid populations. Ladybirds are also important predators of mites, helicoverpa eggs and small larvae.
Scientific name
Common spotted ladybird (Harmonia conformis)
Transverse ladybird(Coccinella transversalis)
Variable ladybird (Coelophora inaequalis)
White collared ladybird (Hippodamia variegata)
Striped ladybird (Micraspis frenata) Minute two-spotted ladybird (Diomus notescens)
Mite-eating ladybird (Stethorus spp.)
Other names
- Three-banded ladybird is also known as maculate ladybird.
Description
Adults:
- 1–7mm long
- round and convex
- varied patterns of orange and black. The mite-eating ladybird is bluish black all over.
Eggs:
- generally yellow and football-shaped
- laid standing on end in groups.
Larvae:
- tapered abdomens, often with prominent tubercles
- more elongated and up to 2mm longer than adults
- usually mostly grey or black with orange markings
- may be covered in spines or white fluffy wax material.
Pupae:
- globular
- similar size to adults
- attach themselves to the plant at their posterior end.
May be confused with
Lacewing larvae are often confused with ladybird larvae. Mealybug ladybird larvae in particular are white and can be easily confused with green lacewing larvae that have been feeding on mealybugs (and camouflaging themselves with mealybug bodies).
Distribution and habitat
Widespread. The presence of adult ladybirds in crops is often an early indicator of aphid activity.
Hosts
- aphids
- whiteflies
- leafhoppers
- thrips
- mites
- scale insects
- helicoverpa eggs and small larvae
Impact on pests
Both adults and larvae are voracious feeders on target species.
Life cycle and ecology
After hatching, most ladybird species pass through 4 immature stages before pupating and developing into the commonly recognised round orange beetle patterned with black spots or stripes.
Factors that influence effectiveness
Refer to the impact of pesticides table in the current issue of the Cotton Pest Management Guide for information on ladybird sensitivity to various pesticides.
Further information
Identifying the larvae of cotton ladybird species—The Beatsheet