Biological Control
Cryptolaemus more info
The Mealybug is one the hardest pests to control. Its body is covered with white waxy threads, which often make a chemical pest control unsuccessful. The predatory beetle Cryptolaemus montrouzieri is a specialist in clearing mealybug populations.
Cryptolaemus montrouzieri is an Australian ladybird. Adult beetles can reach a length of 4 mm, and have black-brown wingcases. Its head, thorax an abdomen are orange-brown. The Cryptolaemus larva can reach a length of 13 mm and can be recognized by its white downy wax secretion. Due to this secretion, the larva and its prey are as like as two peas in a pod. However, the larva of Cryptolaemus is longer, more mobile and its wax threads are longer than those of mealybugs.
The development ture. It takes about 32 days at a temperature of 24°C. A female beetle lives approximately 2 months and lays 10 eggs a day in a mealy bug colony or in a group of mealybug eggs.
Cryptolaemus is most active when the weather is sunny. A temperature of 22-25°C and a relative humidity of 70-80% are optimal for egg laying. The beetle is not active when temperature drops to 16°C
Cryptolaemus is a very efficient predator for clearing mealybug populations. Adults and young larvae eat every stage. Cryptolaemus can also have aphids or scales for a meal as an alternative to mealy bugs, if only few of them are present.
When applying Cryptolaemus in greenhouses, introduce 2-3 adults/m². It is best applied during a cool time of the day. The presence of ants in the crop adversely affects the work of Cryptolaemus. Ants are very keen on the mealy bug's honeydew and therefore protect them against this predator.