Pheromone traps are commonly used to monitor for lightbrown apple moth (LBAM). In Western Australia another species, western fruit moth (WFM), occurs. While these species are almost indistinguishable in appearance it is critically important to know which pest is present in your orchard to decide which pheromone to use. The pheromones are species specific. Use of the wrong pheromone will give misleading monitoring results.

LBAM and WFM are both native to Australia. While LBAM is found in all pome fruit production areas around the country, WFM only occurs in parts of Western Australia. WFM is generally more abundant than LBAM in production areas around Manjimup, while elsewhere LBAM is generally more abundant.

The photo below shows two sticky bases from pheromone traps placed in the same block of a Manjimup apple orchard, the one on the left has a LBAM lure, the one on the right a WFM lure. Note how no LBAM were caught but there were a high number of WFM.

The pheromones for lightbrown apple moth and western fruit moth are species specific. In Western Australia where both species are present it is recommended to use traps for both species to ensure accurate monitoring. These traps for lightbrown apple moth (left) and western fruit moth (right) were placed in the same orchard. (Source: DPIRD)

If you grow around Manjimup you should install monitoring traps with each species specific pheromone for monitoring. In other production areas the LBAM pheromone should be used but you may wish to use WFM traps as well. The different lures must be placed in separate traps so as you can distinguish which moth is present. Place a minimum of  three of each species trap per block, Traps for the same species should be spread evenly over a block, and have 10-30m between any two traps. Lures for WFM are available from one supplier only. Please contact DPIRD for details.

The recommended action threshold for LBAM and WFM in Western Australia is 5 or more moths caught in one trap in one week. When this threshold is reached check trees for larvae. Consider applying control once infestation of shoot/fruit clusters by larvae reaches 5%. Management for LBAM and WFM is the same.

Further information links 

• page 73-78 of the Apple and Pear IPDM manual

Article reviewed by Stuart Learmonth (DPIRP WA) and David Williams (Agriculture Victoria)