Saturday, June 23, 2007

Thoughts on the light brown apple moth

There's an article in today's Bee about light brown apple moth (LBAM) monitoring at Green Acres Nursery in Roseville. Apparently, they receive plants from a Bay Area wholesaler deep in the quarantine area. I'll bet a lot of our local nurseries do.

The article emphasizes that the main concern is not about the potential damage to California plants, but about economic losses in quarantined regions. The San Francisco Bay Area is currently under a Federal Domestic Quarantine Order. Sacramento and the Sierra Nevada Foothills could be next.

If the moth starts showing up in local nurseries, they will face quarantines, which will force them to spray... at first with Neem oil, then with nastier chlorpyrifos if the invasion becomes an infestation. And until they pass agricultural inspection, nurseries presumably won't be able to ship plants.

As a gardener, it begs the question "What if I do a little shopping in the Bay Area and bring my LBAM-laden plants home to Sacramento? Wouldn't that do a disservice to local nurseries trying to prevent LBAM from invading?" Hmmm...

Should we become familiar with all stages of the moth and get ready with the Neem oil if we see it on our plants? Should we ask Bay Area nurseries if they're monitoring for LBAM? Or should we leave the problem to natural enemies of the LBAM, which include the following:

  • Trichogramma wasps.
  • Parasitic wasps Dolichogenidea arisanus and Xanthopimpla spp.
  • Parasitic flies Goniozus spp. and Zosteromyia spp.
  • Predatory bug Ochalia shellembergii
  • Lacewings
  • Spiders
  • Various pathogens

The California Department of Food & Agriculture has put out a nice brochure on the LBAM showing pupal, caterpillar and adult stages and urges you to call 1-800-491-1899 if you discover signs of damage or the insect itself.


  1. I asked them at Annie's last weekend, and they told me they hadn't seen any yet.

    Interesting that there is no indication that they can't ship out of California on the website. Maybe the quarantine is wholesale only?

  2. Interesting. Thanks for passing that on. Annie's is wholesale/retail and ships nationwide, so they might want to put up some traps for monitoring purposes. Maybe they already have.

    Here's what the Federal quarantine says: In California, LBAM-affected counties are quarantined through a two-tiered approach
    that regulates the interstate movement of host articles from quarantined areas based on
    inspection verifying pest- freedom.

    I take that to mean that until the moth is discovered at your nursery or farm and you pass inspection, you can still ship plants. It's not clear to me if the moth was detected at the wholesale nursery.

    The nursery in my area that was in the news had accepted a shipment from a wholesaler in a highly-infested area.

    It was good of them to be up front about the problem. I could see the temptation for nursery owners and farmers to say, "Moth? What moth?" ;-)