Our Pest Control Expert, Julian Ives, has spent many years advising commercial growers and gardeners on the subject of safe and efficient natural pest control treatments.

Here he shares his experience on the problems Mealy Bug can cause in the garden and how to get the best results from the Australian ladybird-based Mealy Bug Killer...

How to Use Mealy Bug Killer
Introduce Mealy bug Killer to greenhouses and conservatories when mealy bug is observed on plants. Mealy bug Killer is supplied in two forms either as an adult Cryptolaemus montrouzieri beetle or larva. The larva is the young stage of the beetle and has no wings. This makes the larvae ideal for spot applications to treat individual plants. The adults are better suited for mass releases against Mealy bugs spread throughout a greenhouse or conservatory. Both stages of the life cycle will feed and consume mealy bugs. The adult beetle is active from temperatures of 23-25.c. The larvae are active at lower temperatures from 17-18.c. Release the adults at night and ensure windows and vents are closed. For the larvae apply about 4-5 larva per infested plant. One pack of 25 adults will treat approx. 12.5 square metres. Repeat applications of larvae and adults may be required when numbers of mealy bug are high.

Appearance and Lifecycle
Mealy bugs have their names due to their appearance. They are often covered in a waxy, mealy, fluffy material that is secreted from their bodies. Their appearance can be similar to woodlice. Females are often pink or yellow. There are several species but the difference between species can be difficult to identify. Some species have to mate before eggs can be laid and others can reproduce asexually. One of the more common species is the Citrus mealy bug, which does have to mate to lay eggs. Females are about 5mm long and wingless. The males are smaller and winged. Females lay egg sacks that develop from nymphs into adults. The life cycle of egg to adult is 46 days at 22C. Colonies of mealy bugs look like sticky cotton wool.

Symptoms and Damage
Mealy bug nymphs and adults feed on plant sap, by removing plant sap the plant is weakened and growth slowed. Leaves will often go yellow or drop off. After feeding the mealy bugs excrete honeydew. The honeydew is sticky and sooty moulds often grow on the honeydew. Mealy bugs can be found on a wide variety of plants and are commonly found on Cacti, Succulents, Orchids, Citrus and Vines. Mealy bugs are normally found in warm greenhouses and conservatories and are at their peak from late summer to the autumn.

Natural Choice Treatments
A natural solution for mealy bug is best achieved with biological pest control. However certain conditions are required for successful use of these predators and parasites, if these are not present its possible to use safe sprays like Savona fatty acid for their control.