Cryptolaemus adult ladybird beetle feeding on mealybug
Denis Crawford
Cryptolaemus
Mealybug predator
Cryptolaemus montrouzieri
Cryptolaemus are Australian native ladybird beetles. They are very efficient natural enemies of mealybugs. Cryptolaemus have been exported to many other countries and are recognised as powerful predators of mealybugs worldwide.
The adult beetle is about 4mm long with an orange head and black wing covers. The larvae grow to 13mm long and are covered in waxy filaments. The larvae look very much like mealybugs and are often confused with them. Adult female beetles lay up to ten eggs per day directly into mealybug eggmasses. They can lay up to 500 eggs in total. Adult beetles and young larvae feed on mealybug eggs and young stages. Large cryptolaemus larvae can also consume adult mealybugs. The life cycle takes from 4 to 7 weeks depending on temperature.
In addition to mealybugs, Cryptolaemus will also feed readily on many species of soft scales including black scale, pulvinaria scale and cottony cushion scale.
Cryplolaemus larvae (larger) and mealybugs
Dan Papacek
Cryptolaemus larva feeding on black scale
Dan Papacek
Target pests
- Mealybugs
- Pulvinaria scales
- Cottony cushion scale
- Soft scales
Mealybugs are serious pests of orchards and vineyards. They also attack many indoor and glasshouse plants. Mealybugs thrive in the protected areas between clustering fruit, in the growing tips of many ornamental plants as well as flower buds and leaf axils. Mealybugs feed by sucking sap.
All mealybugs produce large amounts of honeydew on which sooty moulds grow. They take about four weeks to reach maturity in summer, producing up to 500 eggs in a white woolly egg mass.
Mealybugs are difficult to control with pesticides. This is largely due to their waxy covering, their habit of infesting sheltered plant parts, and the consequent difficulty in achieving effective spray coverage. Mealybugs also readily develop resistance to pesticides.
Suitable crops/environments
Cryptolaemus can be used to control mealybugs in a range of crops and environments. Like many other predatory beetles, cryptolaemus are most efficient when the host is plentiful. Both the adult beetles and the larvae prey on mealybugs. They survive at temperatures of 16 to 33°C but do best in temperatures around 28°C. Adult beetles are most active in sunny weather.
Because cryptolaemus disperse readily, they work best if the mealybug population is large or if the beetles can be contained near the infested crop. Cryptolaemus perform well in glasshouse, nursery and indoor situations.
Before release
In indoor or nursery environments, cryptolaemus are best released whenever mealybugs are present. Best results are obtained when a full release is made early in the season, followed by smaller top- up releases at intervals of between three and six weeks. In orchard environments, cryptolaemus should be released when active mealybugs are present but preferably before the population has built up to high and damaging levels.
Like other beneficial insects, cryptolaemus should be protected from extremes of heat and low humidity. Avoid using insecticides for at least two weeks before release.
At release
Cryptolaemus are supplied in punnets containing a minimum of 40 beetles or in tubs of 500 beetles. The lids of the punnets or tubs should be opened and the beetles dislodged by lightly tapping the container onto plant foliage near mealybug infestations.
Recommended release rates
Orchards: Minimum 1000 beetles per hectare (25 punnets or two tubs per hectare).
Enclosed situations: Minimum one or two beetles per square metre (one punnet per 20 per 40 m2).
Higher rates of release may be required where there is a history of mealybug problems. Regular dribble releases of cryptolaemus are encouraged in nurseries and glasshouses to keep mealybugs at low levels.
After release
After release, beetles rapidly disperse throughout the treated area, laying eggs into the mealybug egg masses. It may then be two or three weeks before cryptolaemus larvae can be seen feeding on the pest. The adult beetles may not be obvious after release.
Regular monitoring by an experienced scout is recommended following release to check that the cryptolaemus have established. Because the younger larvae of cryptolaemus look similar to those of mealybugs, care should be taken not to confuse the two.
Significant control is possible within one generation of cryptolaemus (about four weeks). However, high pest populations may take longer to control and may require booster releases.
Life cycle of Cryptolaemus and mealybugs
Good bug book
Sleeve cage to aid establishment
Dan Papacek
Cultural practices to aid establishment
Adult ladybirds are strong fliers and will establish best if populations of mealybugs are high or if a special effort is made to keep the beetles close to the infestation.
Orchard and outdoor situations: In infested trees, branch netting cages in key locations may help improve establishment. Small shrubs may be covered with a cloth cage as described for plants in enclosed situations.
Enclosed situations: A useful technique is to confine some beetles to one or two heavily infested plants with mosquito netting (or similar material) for a few days while they are laying their eggs. Avoid releasing the beetles where bright lights may attract them away from the release area. In shopping centres and similar situations, it is best to release the cryptolaemus beetles after hours.
Chemical use
Pesticide residues may slow or prevent the establishment of cryptolaemus. Copper and nutritional sprays are generally not harmful and many miticides are also quite safe. Organophosphate, carbamate and synthetic pyrethroid insecticides are very toxic and should be avoided where possible. If these sprays are applied, a minimum of four weeks should elapse before cryptolaemus are released. Prevent drift of pesticides from neighbouring areas. Some insect growth regulators (IGRs) are also harmful to predatory beetles.
Cryptolaemus larvae feeding on Pulvinaria scale
Dan Papacek
Additional information
Cryptolaemus are despatched by overnight courier or express post and should be received within one or two days. Honey is smeared under the lids of the punnets or tubs as food for the beetles. On their arrival, cryptolaemus should be released as soon as possible. In the event of adverse weather such as extreme heat or high rainfall, the beetles may be stored for several days in a dark room at about 17°C. Extra honey should be placed under the lids as additional nourishment. Cryptolaemus are often released with green lacewings to improve prospects for biological control of mealybugs. Ask about our discount offer for lacewings when used with cryptolaemus as a combination treatment.
Other natural enemies of mealybug
- The parasitic wasp Leptomastix dactylopii
- The parasitic wasp Leptomastidea abnormis
- Green lacewings Mallada signata
Video clip - Cryptolaemus feeding on mealybugs
Download Cryptolaemus - mealybug predator .pdf147 Kb PDF
Product Pricing
| Item | Qty. | Price | |
|---|---|---|---|
| Punnet (40 Beetles) | 1 – 19 | $13.20 | |
| Punnet (40 Beetles) | 20+ | $11.00 | |
| Tub (500 Beetles) | 1 – 9 | $132.00 | |
| Tub (500 Beetles) | 10+ | $110.00 |
All prices include GST. Freight and packaging extra.