Codling moth (cydia pomonella L.)

Codling moth adult

Codling moth is a key pest of apple, which attacks the fruit directly causing economic damage at low population densities. It is sometimes very damaging to pear.

The life cycle involves one complete and one partial generation per year in southern Britain, though two generations occur in hot summers.

First generation adults emerge in May to July and fly at dusk on warm evenings. Eggs are laid singly on leaves and the surface of fruits. Larvae hatch after 7 10 days, depending on temperature, and cause damage by boring into the flesh of the fruit. A characteristic entrance hole is left, partially blocked by dry frass.

This readily recognised  pest should be monitored using pheromone traps, monitored weekly from petal fall until harvest. The threshold is a single catch of 5 or more moths per trap per week from May to June (first generation, fruit less susceptible) and 3 per trap per week from August to Setpember (second generation, fruit more susceptible).

Control
In addition to sanitation measures which help reduce the worst ravages of attack, there are three different approaches for controlling codling moth:

  1. biological control with sprays of the codling moth granulovirus
  2. chemical control with sprays of insecticides which are either ovicidal, larvicidal or both
  3. sex pheromone mating disruption using an autoconfusion system.

Biological control 

Now that the codling moth granulovirus (Carpovirusine, Cyd-X, Madex Top) is available, it should be used wherever possible, bearing in mind the following limitations:

  • It only controls codling moth and not tortrix moths, blastobasis or other pests
  • A maximum of ten sprays each (Madex Top) giving 8-14 days protection is allowed per season (a maximum of six sprays per generation)
  • Application should be made just before egg hatch is expected to ensure larvae pick up virus particles as they move from the egg to the apple entry point. Application a little bit too early is preferable to a little bit too late.
  • Heavy attacks may result in some superficial sting injury as the young larvae hatching from eggs do not die immediately.

Chemical control

A chemical control programme should comprise a series of sprays of insecticides at 2-3 week intervals, maintaining an insecticide deposit throughout periods of risk.

  • The interval between sprays should be 2 weeks if temperatures are high or if the risk is high.
  • The choice of insecticides is chlorantraniliprole applied at or shortly before the onset of egg laying or spinosad (Tracer) applied at the onset of egg hatch.
  • Pyriproxyfen (Harpun) can also be used as an alternative which is first applied up to 24 hours after egg laying. It inhibits egg hatch. It can also be applied later to inhibit metamorphosis of nymphs to adults. It also reduces the fecundity of adult females.
  • Use of synthetic pyrethroid insecticides, which are very effective, should be avoided as they are harmful to predatory mites and many other important natural enemies.
  • The onset of egg laying is when a threshold pheromone trap catch is exceeded.
  • Egg hatch occurs 7-10 days later.
  • The interval between egg laying and egg hatch can be estimated more precisely by accumulating percentage egg development amounts calculated from daily maximum and minimum air temperature.
  • First egg hatch is expected when the accumulated sum reaches 100%.
  • Be vigilant for second generation attacks, which occur in August in hot summers.

Products approved for control of codling, tortrix moths or caterpillars on apple

Choice of insecticides – efficacy factors
Active ingredient Trade name (examples) Class1 Selectivity Label rec’s2 Safety to Typhs Suggested interval between sprays (days)
adoxophyes orana granulovirus Capex microbial biocontrol highly selective sft safe none stipulated
Bacillus thuringiensis var. kurstaki  Delfin WG, Lepinox Plus bacterial selective c safe 7
chlorantraniliprole Coragen (EAMU 0303/22) anthranilic diamide selective c safe none stipulated
codling moth granulovirus Carpovirusine, Cyd-X, Madex Top microbial biocontrol highly selective cm safe 8 sunny days
deltamethrin Decis Forte etc pyrethroid broad spectrum c, cm, t harmful none stipulated
pyriproxyfen Harpun metamorphosis inhibitor selective cm safe none stipulated
spinosad Tracer neural blocker selective C, cm, ftt,sft safe u
Choice of insecticides – Safety factors
Read and follow the label before applying any sprays		  
  Hazards3 Harvest interval (days) Max. no. sprays Buffer zone width (m)
Anticholin-esterase? Humans Fish & aquatic life Bees
adoxophyes orana granulovirus no u u u 0 u 0
Bacillus thuringiensis var. kurstaki no u u u Varies with product Varies with product 5
chlorantraniliprole no h ed h 14 1 30
codling moth granulovirus no h,i u u Varies with product Varies with product 0
deltamethrin no h,i ed d 7 u 50
pyriproxyfen no d t u fruit diameter up to 40mm 2 20
spinosad no u ed h 7 4 40
Keys:     1CSI=chitin synthesis inhibitor, JHA=juvenile hormone analogue MAC= moulting accelerating compound 2c=caterpillars, cm=codling moth, ftt=fruit tree tortrix, sft=summer fruit tortrix,  t=tortrix, wm=winter moth 3d=dangerous, ed=extremely dangerous, h=harmful, ir=irritant,  t=toxic u=no hazard specified  

Control in organic orchards
Organic growers should use multiple codling moth granulovirus sprays (up to 6 applications per generation and not exceeding 10 applications per season for Madex Top) and in combination with season-long maintenance of a pheromone autoconfusion system.

  • Note that Bacillus thuringiensis has little effect on codling moth.
  • Cultural control remains an important additional measure.

Further reading

Codling moth - additional information