Lightbrown apple moth		Greenheaded leafrollers		Brownheaded leafrollers
	Action thresholds for lightbrown apple moth and other leafrollers

The action threshold for spraying to control lightbrown apple moth and other leafrollers is a cumulative moth catch of 30 moths at a single trap site since the start of trapping or since the last spray. Usually this refers to a single trap for lightbrown apple moth, but where other species are also being monitored, the catches of all the leafroller traps at the site are added together. These threshold can be used for chemical control or spray applications of Bacillus thuringiensis. The minimum interval between sprays depends on the period of efficacy of the spray used. For instance, even if the threshold is exceeded in the week or two following a Mimic® spray, this product should be applied no closer than 21 days apart. On the other hand, the field efficacy of Bacillus thuringiensis, as used by organic growers, is 1-2 weeks.

A further action threshold is used in IFP. In northern districts, a check that initial control of the first generation leafroller has been achieved, can be done in conjunction with blackspot and powdery mildew sampling. If a leafroller larva is found on any shoots examined, or two leafroller damaged fruit are found out of the 1000 examined, then a spray of Mimic®, Success Naturolyte®, Match® (check withholding period) or Alsystin® (check withholding period) should be applied.

More details are available on the use of these thresholds in IFP