Various insecticides that are approved for control of colding moth, totrix moths or for general caterpillar control are likely to control summer fruit tortrix moth.
- Summer fruit tortrix moth may be controlled with indoxacarb (Steward or Explicit), spinosad (Tracer), or with the biocontrol agent Bacillus thuringiensis, applied to coincide with egg hatch, usually in June.
- Chlorantraniliprole (Coragen) is also thought to offer incidental control when applied against codling moth.
- Pyriproxyfen (Harpun) may also offer incidental control of summer fruit tortrix moth when applied for codling moth control. It inhbits egg hatch, metamorphosis of nymphs to adtuls 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 summer fruit tortrix moth.
- Bacillus thuringiensis is considered to be of only moderate efficacy.
- The summer fruit tortrix ganulovirus (Capex) is another option. Highly specific to summer fruit tortrix, it is ideal for use in organic and IPM production systems and has no harvest interval or buffer zone requirement. See information on viruses in biological control section below.
- The first spray should be applied at the onset of egg hatch of the first generation. Further sprays should be applied at 7-10 day intervals until the egg hatch period has ended.
- Synthetic pyrethroids are highly effective but their use should be avoided as they are harmful to predatory mites and other beneficial insects.
- A pre-blossom spray of indoxacarb (Steward or Explicit) or methoxyfenozide (Runner), often applied to control early season caterpillars, will reduce populations of overwintered summer fruit tortrix moth caterpillars, but is unlikely to be sufficiently effective to prevent damaging first and second generations developing subsequently.
- The onset of egg laying is taken as the date when the pheromone trap catch exceeds 5 moths/trap/week.
- If traps are only examined weekly, the date when this occurred can often be pin-pointed more accurately by examination of daily temperature records.
- The moths fly when dusk temperatures exceed 15°C.
- The onset of the egg hatching period occurs 7-21 days later, depending on temperature. It can be calculated accurately from daily maximum and minimum air temperatures using the look-up table (see ‘Forecasting’ ).
- The daily percentage egg development amounts are summed from the date of the onset of egg laying. When the sum reaches 90%, egg hatch is imminent and the first spray should be applied.
- A second generation occurs in August and September which can be damaging on later harvested varieties. The second generation may be controlled in the same way.