Fruit tree tortrix moth (Archips podana (Scolopi))

Tortrix damage to leaves

Fruit tree tortrix moth is a moderately important pest of apples and pears in the UK.

The life cycle is simple with the pest overwintering as a second or third instar larva which emerges in spring after bud burst and feeds on the trusses. Pupation occurs after blossom and first generation adults fly in June and early July.

Eggs are laid in batches on foliage and hatch after 2-3 weeks. Adults are readily recognised but larvae may be confused with other caterpillar species.

Larvae feed in leaf rolls and on the surface of fruits making the characteristic damage of small holes in the flesh.  Later in the season, near to harvest, larvae make larger surface excavations in the flesh of fruits. There is a partial second generation in August and September.

The pest should be monitored with pheromone traps weekly from petal fall of apple to the end of August. The economic threshold for treatment is >30 moths per trap per week.

Control

Several insecticides are approved for control of tortrix moth and/or other caterpillars on apple and/or pear in the UK.

  • The pest may be controlled with a spray of Bacillus thuringiensis (Dipel DF) or spinosad (Tracer), applied to coincide with egg hatch usually in late June or July about 2 weeks after the threshold pheromone trap catch is exceeded.
  • Synthetic pyrethroids are highly effective but their use should be avoided as they are harmful to predatory mites and other beneficial insects.
  • Spinosad (Tracer) will also control codling moth.
  • Codling moth flies slightly earlier than fruit tree tortrix moth but sprays of these insecticides applied for codling moth usually also give good control of fruit tree tortrix moth.
  • Chlorantraniliprole (Coragen) is also thought to offer incidental control when applied against codling moth.
  • Pyriproxyfen (Harpun) may also offer incidental control of fruit tree tortrix 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 fruit tree tortrix moth.

Insecticides approved for use on apple which are recommended to control fruit tree tortrix moth or offer some incidental control when applied to control other pests

Choice of insecticides – efficacy factors
Active ingredient Trade name (examples) Class1 Selectivity Label rec’s2 Safety to Typhs Suggested interval between sprays (days)
Bacillus thuringiensis var. kurstaki Dipel DF, Lepinox Plus bacterial insecticide selective to caterpillars c safe 7
chlorantraniliprole Coragen (EAMU 0303/22) anthranilic diamide selective c safe none stipulated
deltamethrin Decis Forte etc pyrethroid broad spectrum 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 factor
Read and and follow the label before applying any sprays
  Hazards2 Harvest interval (days) Max. no. sprays Buffer zone width (m)
Anticholin-esterase? Humans Fish & aquatic life Bees
Bacillus thuringiensis no u u u Varies with product Varies with product 5
chlorantraniliprole no h ed h 14 1 30
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 2c=caterpillars, ftt=fruit tree tortrix, sft=summer fruit tortrix,  t=tortrix, wm=winter moth 3d=dangerous, ed=extremely dangerous, h=harmful, i=irritant,  t=toxic, u=no hazard specified

Control in organic orchards
Fruit tree tortrix moth often causes significant fruit damage in organic orchards.

  • If control measures are necessary, sprays of Bacillus thuringiensis (Dipel DF) or, if it is permitted in organic production, spinosad (Tracer) should be applied in the same way as in conventional orchards (see ‘Biological and chemical control’ ).

Further reading

Fruit tree tortrix moth - additional information