Cryptolaemus montrouzieri

Cryptolaemus was one of the first successes of biological control. It was export from Australia to California in 1891 to control citrus mealybug

This brown australian ladybird eats all stages of Mealybug. In the UK it is used only in the warmth of conservatories or glasshouses, as it is not normally warm enough outside, and also the ladybirds tend to fly away. It needs high warmth and light levels to work efficiently, so it is best introduced in June to give a good 3 months of the summer before the cooler weather sets in. Cryptolaemus settle best when there are quite a large number of Mealybugs to attract them.

Unfortunately Cryptolaemus can be killed or damaged by insecticides, so its best to stop using these well before they are introduced. Soft soap can be used to wash off the plants if you are waiting for warm weather.

Cryptolaemus are sent to you as larvae. The larvae will also eat the mealybugs. They are voracious feeders, and if they can't find enough food, they will eat each other! Cryptolaemus larvae look very like mealybugs themselves so be careful to distinguish. They are about 1cm long, with a white waxy coat, and they are slightly larger and more active  than their prey.

If the ladybirds are well fed they will start to breed. They start laying eggs on the mealybug wool about 5 days after reaching adulthood, and can produce as many as 500 eggs. The total length of the life cycle depends on temperature - 25 days at 30 degrees C or 72 degrees at 18 degrees.

Standard pack of 10 gives good coverage for an average conservatory where the problem is not severe. The large pack is needed where the infestation is advanced or the area larger.

Read more about the australian ladybird here