Several insecticides are approved for control of codling, tortrix moths (light brown apple moth is a tortricid) or caterpillars on apple. As light brown apple moth is a comparatively new pest to Britain we have only limited experience in controlling it with insecticides and comprehensive efficacy trials have not been done.
- However, experience has shown that indoxacarb (Steward or Explicit) is effective.
- Chlorantraniliprole (Coragen) is also thought to offer incidental control when applied against codling moth.
- Pyriproxyfen (Harpun) may also offer incidental control of light brown apple moth when applied for codling moth control. It inhibits egg hatch, metamorphosis of nymphs to adults and reduces the fecundity of adult females. However, as a new product to the UK in 2020, further experience is required to inform growers and agronomists of its efficacy at controlling light brown apple moth.
- On cherry, Bacillus thuringiensis (Dipel DF) has given disappointing results.
- Spray programmes applied for control of codling and tortrix moths on apple are likely to give good incidental control of light brown apple moth.
- However, special control measures may be required if damaging populations of the pest develop.
- Sprays should be timed according to sex pheromone trap catches.
- Larvicides should be applied 7-10 days after a threshold catch of 30 moths per trap is reached, with sprays repeated at fortnightly intervals to give protection through the egg hatch period.
- For details on how to use the various available insecticides, see Fruit tree tortrix moth.
Insecticide resistance
- Bacillus thuringiensis (Dipel DF) has been used to control light brown apple moth although some populations have become resistant and there is some evidence of avoidance of Bt contaminated food by the larvae.