Natural Defense Against Vineyard Pests
Located in the hills east of the town of St Helena, Spring Mountain Vineyard has long been known for its environmentally friendly grape growing and winemaking practices. When vineyard manager Ron Rosenbrand discovered the destructive mealybug in 5 acres of Cabernet Sauvignon and Merlot, conventional treatments seemed like the only option.
As reported by the St Helena Star, Rosenbrand tried to combat the mealybug with insecticides and quarantine measures for 3 years, but to no avail…
> “I thought, there’s gotta be another way to do this. We weren’t eradicating and barely controlling the vine mealybug. And with our methods, we were still seeing some spread through the blocks.”
Rather than continuing to fight the bothersome pest with questionably effective pesticides, Rosenbrand decided to take a different approach. In collaboration with a team of UC Berkeley researchers, he released 6 species of insects that are natural predators of the mealybug. These included ladybugs, mealybug destroyers, 2 species of wasps, green lacewings, and minute pirate bugs.
The insects seem to be effective, and Rosenbrand is cautiously optimistic. “I have no idea if this is able to eradicate or control the Vine Mealybug, but I would much rather use biocontrol as a control method than insecticide. It is better for our environment and we’re hoping that last year wasn’t a fluke, but a demonstration of how biocontrol methods can work. We’ll see how things go through this season and by November, if we have similar results, we’ll be able to say we’re controlling and possibly eradicating vine mealybug.”
Natural predators have been used to combat other vineyards pests, notably the glassy winged sharpshooter. Tiny wasps (Gonatocerus triguttatus) have been released in several parts of California to control the spread of the glassy winged sharpshooter.