Light Brown Apple Moth

Light brown apple moth (LBAM) is certainly more than one garden word, but these Australian invaders have been on the agricultural radar since they were first seen in 2007. You can protect apple and many other crops across the nation by knowing what to look for as you play in your garden.

Light brown apple moth (Donald Hobern) CC BY 2.0

A quarantine is in place for the light brown apple moth (Epiphyas postvittana). You can track down a map of your area, if you live in California, at the CA Dept. of Food & Agriculture Boundary Index Map. If you live outside of California, you can contact your local Cooperative Extension Office for more information.

​Damage caused by light brown apple moths

It’s hard to get motivated to add one more thing to your to-do list, I know, but here are some good reasons for becoming aware of this particular pest:

• LBAM attack apple trees, grapes, and hundreds of other vegetable crops
• can kill strawberries, blueberries, and blackberries and other cane fruit 
• larvae feed on and damage buds as they emerge in early spring
• larvae then feed on flower clusters as they bloom
• as fruit develops and begins ripening (veraison), larvae feed on the fruit, creating points of entry for other pests and diseases
• since these pests do not rest in winter, they continue feeding and damaging nearby plants​

​So, as soon as your plants start producing, light brown apple moth larvae start causing problems. As with other invasives, this pest has no natural enemies.

Light brown apple moth (Danny Chapman) CC BY 2.0

​LBAM identification

Light brown apple moths look similar to other leafroller moth (Tortricid) species. According to UCANR, they “hold their wings over their abdomens in a bell shape when at rest and have protruding mouthparts that resemble a snout.” Adult moths rest on the underside of leaves during the day. At night, females emerge and lay eggs on the tops of leaves, near the edge. Eggs are laid in masses of 50 to 150 and they look like overlapping fish scales. At first, these clusters are covered with a greenish slime, but this dries up and sloughs off as the embryos grow and become darker. Larva emerge after 1 to 2 weeks. They reach a length of ½ to ¾ inch and are pale green, with a yellowish-tan head. Just behind the head is a greenish-brown area. Webbing may be seen on shoot tips as larva spin nests, using new leaves and flower parts as protection. As they approach maturity, larva feed heavily on leaves, creating the rolled leaf marker common to the tortrix family. 

Since DNA testing is required for proper identification (and since this pest has the potential to cause so much damage), any captured moths or larva should be taken alive, if possible, to your county agricultural office for identification.

Female light brown apple moth, dorsal ((Ken Walker, Museum Victoria) CC BY 3.0 au

Male light brown apple moth, dorsal (Ken Walker, Museum Victoria) CC BY 3.0 au

How to control light brown apple moths

These pests can be treated the same way as other members of the tortrix family. This means:

• remove mummies and fallen fruit as soon as they are seen
• maintain a welcome habitat for parasitic wasps, such as the beloved braconid wasp
• remove nearby broadleaf weeds
• spray with Bacillus thuringiensis (Bt), as needed
• keep a lookout for the pests year round
• male LBAMs can be captured with pheromone traps​

Maybe we need to create a series of Old West style wanted posters for all these garden pests. Any interested artists out there?