The best predator to attack mealybug is the brown Australian Ladybird "Cryptolaemus montrouzieri"
Sold in 2 sizes and as adults or larvae. Orders placed by 10am Friday will be despatched early the following week by Royal Mail Special Delivery.
The larvae hatch out as voracious predators of mealybugs. Young larvae and adults prefer the smaller stages of mealybug, whereas the large larvae will eat mealybugs of any size. If mealybug is in short supply, Crytpolaemus may also eat young scale insects.
In the UK they are used only in the warmth of conservatories or glasshouses, it is not normally warm enough outside and the adult ladybirds tend to fly away. The Ladybirds need warmth and light to work efficiently, so are best introduced from April onwards, unless you live in the south and west where the spring is earlier. Cryptolaemus settle best when there are quite a large number of Mealybugs to attract them.
Cryptolaemus was one of the first discoveries in the science of biological control. This little beetle known as "the Australian Ladybird" was first exported from Australia to California in 1891 to control citrus mealybug.
Unfortunately Cryptolaemus can be killed or damaged by insecticides, so its best to stop using these well before they are introduced. SB invigorator or another soft soap can be used to wash off the plants if you are waiting for warm weather.
Instructions for use
Cryptolaemus are sent to you as either larvae or adults. They are voracious feeders, but if they can't find enough food they will eat each other! Cryptolaemus adults look like brown ladybirds. Their larvae are white and waxy, they look very like mealybugs themselves.
Cryptolaemus is a strong flier so if vents and doors are left open near to the treated plants they need to be netted over to prevent the Cryptolaemus from escaping.
The Cryptolaemus are posted to you directly from the breeders, in Kent, to minimise the time and losses that occur in transit. Standard pack of 10 gives good coverage for an average conservatory (2-5 sqm) where the problem is not severe. The large pack is needed where the infestation is advanced or the area larger (over 5 sqm). When you get your tube release the contents gently onto the mealybug wool - they can smell their prey and won't get lost!
Cryptolaemus do best in high light conditions with temperatures above 20°C. To enable Cryptolaemus adults to begin to work they need several hours of sunlight and temperatures of 20°C plus each day to enable them to warm up so they can fly. Larvae do not require the sunlight but do need the 20°C plus temperature. Thus, it is recommended that larvae are used during the cooler months and either stages when it is warmer (approx. Spring to late Autumn).
At lower temperatures they will become increasingly inactive and below 9°C they will cease to move at all, but will not actually die until nearer freezing.
The female Cryptolaemus lays her eggs amongst the white cottony egg mass of the mealybugs, and the eggs hatch in 8-9 days at 21°C, or 5-6 days at 27°C. The young larva sucks out the body contents of eggs and young mealybug nymphs, passing through four stages before pupating on nearby stems or leaf undersides. The larval stages take between 12 and 21 days, depending on temperature, and once hatched the adult will live about 3 weeks.
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°C or 72 days at 18°C.