Cryptolaemus montrouzieri larvae are natural predators of mealybug. They consume large numbers of mealybugs in greenhouses, conservatories or heated areas providing natural control on cactus, succulents and many other greenhouse plants. The larvae will ferociously feed on mealybugs until they pupate into the adult Cryptolaemus around 21 days after application. These adults then also continue to feed on any mealybugs left.
Mealybugs are white and fluffy in appearance and damage plants by sucking out the vital sap. They produce a sticky honeydew which sooty mounds of mould can grow on stunting and distorting leaf growth.
Mealybug predator larvae will feed on all stages of the mealybug life cycle including eggs, larvae and adults. If mealybug is not available to prey on Cryptolaemus will also feed on aphids and scale insects at a lower rate.
Cryptolaemus larvae are generally only used in heated environments in the UK. They require a temperature of at least 16 degrees to begin feeding on mealybug. Optimum control is found between 20-25 degrees with high levels of light.
Dragonfli expert Julian Ives advises applying Cryptolaemus larvae at the following rate;
Light infestation – 10-20 per square metre
Heavy infestation – 20-40 per square metre
Repeat applications may be required on heavy infestations, add more adults every 2 weeks until populations of Cryptolaemus can be observed on the plant and control is achieved.
Apply larvae directly onto the foliage and onto infested areas, this should ideally be done in the evening. You can also use our distribution boxes adding the carrier material evenly into these, larvae will then make their way out in search of prey.
With suitable conditions and adequate levels of prey the larvae will feed for around 3 weeks before developing into adults. The adults themselves then have a life cycle of around 25 days, in this time they should also breed, producing a further generation of larvae. Repeat applications may be needed on large infestations, apply new larvae every 2 weeks until Cryptolaemus levels can be observed on the plant and control is achieved.
Please Note; Cryptolaemus is a living creature and can be affected by any chemical pesticides used within the previous few weeks. As a guide cease using pyrethrum or SB plant invigorator 2 days prior to use and other persistent chemicals or universal bug killers 1-2 weeks before using Cryptolaemus.