Many species of Lepidoptera lay their eggs on to commercial crops where their caterpillars can cause enormous damage. The main biological control commercially available against eggs is the parasite Trichogramma although Macrolophus and lacewing larvae will both feed on moth eggs as well as young caterpillars. Lepinox (Bacillus thuringiensis var Kurstaki) is a spray with both curative and protective activity for caterpillar (Lepidoptera / moth larvae). Pheromone traps can be used to monitor adult moth activity of a number of species.

    Type: Insect parasitic nematodes. 

    How it works: Application releases nematodes which seek out insect larvae and in some cases pupae. 

    Species controlled: Overwintering stages of codling moth (Cydia pomonella) and oriental fruit moth (Cydia molesta) and other caterpillar species. Also used for shore fly (Ephydridae) and can be used for large pine weevil control. 

    When to use: Caterpillar foliar spray or soil drench when pest first seen. Codling moth or Oriental Fruit moth September to October. Temperature range 14 - 30°C. 

    Rates of use: Caterpillar (Noctuidae & Pyralidae), wet areas first, spray directly onto caterpillars. Repeat 5 - 7 or 7 - 14 days. 50 million per 100 m2. Codling moth and Oriental Fruit moth, overwintering stage: apply when trunks and soil are thoroughly wet as a coarse spray to remain wet for at least 8 hours. 50 million per 30 m2.

    Type: A minute parasitic wasp. 

    How it works: Adult wasp lays its own eggs inside the eggs of many moths. 

    Species controlled: Many, although it tends to be more efficient where groups of eggs are laid together. 

    When to use: Use as part of an integrated approach in combination with pheromone monitoring (see below under traps), to detect the presence of adult moths and to time sprays of Lepinox (Bacillus thuringiensis). 

    Rates of use: 10 wasps per 1 m2 per week from May to September. Should be used all year round where supplementary lighting is used.

    Trichogramma adult moth eggs
    (Photo: Holt Studios)