Here’s an interesting news pick from ScienceDaily.com, Surprise in the Organic Orchard — A Healthier Worm in the Apple.

The proverbial worm in the apple, the codling moth caterpillar, has been controlled in European orchards for years with a baculovirus called codling moth granulovirus (CpGV).

But in southwest Germany, some organic apple growers noticed that the virus was losing its effectiveness. Pest resistance to chemical insecticides is common in agriculture, but resistance to viruses had never been a problem in the past.

However, as reported recently in Science magazine, a single gene in the codling moth can make it 100,000 times less susceptible to the granulovirus. This highlights the need to anticipate the risk of resistance in pest control, not only for insecticides but also viruses.

When you’re dealing with a strong selection pressure, whether it is an insecticidal spray, or a virus, you’re going to eventually find resistance evolving in your pest. I suppose they thought that viruses would evolve along with the resistance to those viruses, but if you’re spraying them like crazy you can’t hold them back. That’s why you need to have resistance management plans, like planting buffer zones and using integrated pest management.
This should serve as a bit of a wake-up call, calling into question the assumption that only certain kinds of agricultural treatments should be monitored for resistance and not others. There are insects and other critters out there that want to eat the crops we’re growing, and constant research is required to make sure that someday they won’t take the farm.