ShareThisThe answer to a multibillion-dollar question now emerging in the vineyards of California might lie in a series of modest buildings on the edge of Santa Paula.
There workers at Associates Insectary are developing what president and general manager Brett Chandler called a "one-two punch" in the fight against the vine mealybug, a pest that threatens to suck the life out of the vines and grape clusters to which it attaches itself, damaging the state's $2.2 billion wine grape crop in the process.
Punch No. 1: Cryptolaemus montrouzieri, also known in agriculture circles as the mealybug destroyer.
The insectary began rearing the beneficial beetle more than 80 years ago to combat mealybugs in the citrus orchards of Ventura County; it now is the only insectary producing the Cryptolaemus beetle in the U.S., Chandler said.
Punch No. 2: the tiny parasitic wasp Anagyrus pseudococci, which the insectary began raising on an experimental basis in January after an inquiry about its availability by a group of wine grape growers in the Napa Valley.
"The beetle likes to eat the younger mealybugs, while the wasp prefers to lay its eggs in the older mealybugs. That's how we get the one-two punch: They prefer different stages," Chandler said.
The project began with the arrival of 300 "starter" wasps, which measure 1 to 2 millimeters each, from a research colony maintained by UC Berkeley. Chandler declined to identify specific potential customers for wasps reared by the insectary, citing proprietary business concerns. But they could be ready for deployment by midsummer, he said.
"The use of beneficial insects is critical to maintaining a sustainable approach to pest management," said Jon Ruel, vice president of the Napa Valley Grapegrowers and director of viticulture and winemaking for Trefethen Family Vineyards in Napa Valley.
Ruel said he was not aware of the specifics of the Associates Insectary project. "But I'm excited at the prospect of having these bugs, these natural enemies of the vine mealybug, to use in the vineyards," he said.
And prime vine mealybug time is approaching. After spending the winter hidden in the soil and under the bark of the grapevine canes, the invasive pest is ready to emerge after the cool, wet weather of early spring, Ruel said.
"They follow the cycle of the vines. So when the vines wake up, so do the bugs," he said.
The vine mealybug project, and the addition of a second beneficial wasp to its menu of offerings, marks the first time that Associates Insectary has worked with a group other than its members since it was founded in 1928 as a grower-owned cooperative, Chandler said.
In addition to the beetle, the insectary produces Rumina decollata, a snail that preys on the common brown garden snail; Neoseiulus californicus, which controls the Persea mite in avocado orchards, and Aphytis melinus, a beneficial wasp that is able to pierce -- and lay its eggs in -- the armor-clad surface of California red scale, a scourge of citrus groves.
Other insectaries have attempted to rear the Anagyrus wasp with limited success, Chandler said. "Everyone has been able to raise a few hundred at a time, but you need to raise a few million to make it feasible."
Associates Insectary was approached in part because of its reputation for rearing beneficial bugs using natural rather than artificial food sources, which often include a protein pudding, Chandler said.
The food in this case consists of citrus mealybugs, Planococcus citri, which already exist in Ventura County and are similar enough to vine mealybugs, Planococcus ficus, to appeal to the beneficial wasps and beetles.
At the insectary, citrus mealybugs develop while clinging to potato shoots that are kept in complete darkness, the better to control the plants' chlorophyll and carbohydrate levels.
If those levels aren't to the citrus mealybugs' liking, they may not produce a large population. And if there aren't very many mealybugs total, the Cryptolaemus beetle and Anagyrus wasp may fail to find enough of them at the preferred stage of development.
(Lisa McKinnon is a reporter for the Ventura County Star in California.)
