Central California Fig Growers Fool Wasps to Grow Fruit
When it comes to frustration, it would be hard to top the experience of a tiny wasp responsible for the production of what some say is the nation's tastiest fig.
For decades, growers of figs in the Valley have been tricking the wasp and fooling Mother Nature in order to pollinate the flowers -- which are inside, not outside -- a certain variety of fig.
They do it with paper bags, stapling them to branches of calimyrna figs and putting inedible fruit from the caprifig inside the bags. The caprifig provides the pollen for the female calimyrna.
What follows is pollination without the buzz.
Bees need not apply.
"You have to have the wasp from the caprifig," said Richard DeBenedetto, a Chowchilla grower, as he stood in his orchard where fig trees and paper bags stretch across slightly rolling land.
DeBenedetto has 1,200 acres of calimyrnas. The central San Joaquin Valley is the only place in the United States where the figs are grown. The annual value of all fresh and dried figs totals almost $38 million statewide, and most of the fruit is produced in Madera and Merced counties.
DeBenedetto explained how the wasp from the caprifig does her thing.
The stingless wasp, so tiny it can slide through the eye of a needle, works her way through the eye of the caprifig. The wasp, called Blastophaga psenes, then enters the calimyrna.
That's when the trickery begins.
Though the wasp could lay eggs in a caprifig, she can't do so in a calimyrna. She wanders about, trying to insert her ovipositor, which lays eggs, into parts of the plant that are too lengthy. As she wanders, frustrated, she pollinates the flowers.
"Eventually she dies from sheer exhaustion, or old age, and is broken down by a protein-digesting enzyme [ficin] inside the fig," according to Waynes Word, an online textbook of natural history.
It's the seeds from pollinated flowers, not the remains of wasps, that puts the crunch into figs.
If the Blastophagas did manage to lay eggs in the calimyrnas, the result for fig fanciers could be a mouthful of fig wasps.
A single caprifig can be home to as many as 400 of the wasps. The wasp lives less than 24 hours.
DeBenedetto showed a tall mesh screen that separates a small plot of caprifigs from the calimyrnas. Insects from the caprifigs can carry diseases into the calimyrnas at certain times of the year and over-pollination would mean tiny fruit.
The use of the wasp is believed to be the oldest form of man-manipulated insect pollination.
DeBenedetto said it costs from $100 to $120 an acre to perform the pollination routine. He said it takes "10 guys two weeks to get the job done." It happens in June each year, and the calimyrnas are harvested between mid-July and mid-August, "when the weather is the hottest and we have the warmest nights."
DeBenedetto and other growers sometimes get caprifigs from commercial grower Butler Ranches in Tulare County.
Bob Butler said one of his grandfathers planted the caprifig orchard east of Orosi in 1922. Another grandfather purchased it and, along with Butler's father, established the business that has sold millions of pounds of caprifigs to fig growers around the Valley.
The figs with the wasps inside sell for $80 to $85 for 1,000 pounds.
"It's really labor intensive," Butler said. "We have to pick the winter [caprifig] crop off and cut the winter figs open. We have to treat them with a fungicide and hang the figs back out on the trees to pollinate our own crop."
The fungicide is used to keep from spreading diseases to the calimyrnas.
The Butler Ranches also grow lemons and oranges, and, over the years, the acres of caprifigs have declined from 55 to 15. The number of growers in Fresno County dropped by about 40 as decades passed, Butler said.
Growers such as Butler, 72, Debenedetto, 63, and Roy Jura, 77, have seen significant changes in the industry. The constants have included the wasps and the bags.
Jura remembers picking caprifigs when he was a child. He also recalls spreading other fruit out in "dry yards." Debenedetto pointed out trees more than 20 years older than he is.
The three men have seen houses take the place of fig trees, especially in Fresno County. They watched the demand for dried fruit, such as raisins and figs, decline as fresh fruit from the Southern Hemisphere came into stores nationwide.
"In the last 10 years, we lost 50 percent of the major fig growers," Debenedetto said. But Debenedetto said demand has started to rise in recent years.
"It's now picking up because of people who are health-conscious and realize how rich figs are in potassium, fiber and calcium."
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Source: Knight Ridder/Tribune Business News