They’re creepy, they totally disregard personal space, and they love Santa Maria berries as much as the next guy. They are pests of the winged, multi-legged variety that like to fly in your face or jump on your produce when you least expect it. And they’re here in Santa Barbara County, eating and mating and having a grand time.
While Santa Maria strawberry fields and surrounding rows of fruits and vegetables have drawn local pests for as long as they’ve been growing, they’ve also attracted hungry creatures from other time zones or continents—opportunists that hitch rides into the area on this or that, maybe accidentally tucked into someone’s car or hiding in berries sent clandestinely through the mail.
Enter the California Department of Food and Agriculture Plant Health and Pest Prevention Services, with agents that have to be the rock stars of the ag industry—a significantly profitable industry in Santa Barbara County. They should wield guitars, or maybe even capes, but instead they carry traps and clipboards for their collecting, monitoring, and reporting duties.
Thinking small
David Asakawa sat behind a table littered with what at first glance looked like Chinese takeout boxes. With a
closer look, however, it was obvious that they were something more important. They were, in fact, traps used in the field to detect the presence of non-native pests, like the recently arrived vinegar fly.
Asakawa is a senior agricultural biologist for (take a deep breath for this one) Pest Detection/Emergency Projects of the Department of Food and Agriculture’s Plant Health and Pest Prevention Services division. His office’s mission is to detect pests, and to do so quickly. In short, he prevents infestation.
Several of the triangular cardboard pieces on his desk have sticky bottoms and some sort of bait. They will hang on orchard trees and in other areas where pests may attack. What looks like a glass vase is a special trap for fruit flies: It holds water and yeast pellets, which provide the protein females need to lay eggs. Other traps use minute amounts of pesticide to kill pests, or trap bugs on a sticky surface. Some traps use pheromones to lure pests, but not all pests are attracted by such chemical come-ons.
“When pheromones don’t attract them, we go after what they like to eat,” Asakawa said.
In the case of the fruit fly, that means water and protein or sugar. The California Farm Bureau Federation reported that banana slices and apple cider will work to attract the vinegar fly. Asakawa didn’t seem amused by that suggestion: He stated that his office only uses procedures that are approved, regulated, and a matter of policy.
And then he remembered a time when he was working in Southern California, battling red imported fire ants, which aren’t attracted to pheromones. He said apple butter has been used to attract them, but their favorite food is fat.
“In a basket, we attached a cube of Spam,” he explained. “It’s very oily and attracts the ants. The ants send out foragers to find food, and so there are trails that go back to the colony, and that’s how we find them.”
When searching for pests—such as a recent effort to explore the local vinegar fly population—Asakawa’s division places the traps all over the county, mostly in urban areas that are densely populated. The more populated the area, the more traps are placed. Workers generally set up five traps per square mile in urban areas. They then monitor and move the traps at specific intervals.
With this type of surveillance, inspectors are typically able to detect pests early on in their encroachment, giving fighters the ability to deal with bugs by eradicating them, controlling them, or monitoring them further to see if they’re indeed calling the area a new home.
New on the scene
The latest pest to join the Santa Barbara County party is the vinegar fly, which—at only two millimeters long—literally flew in under the radar, sneaking in undetected until it was too late.
The vinegar fly is what’s known in scientific circles as a drosophila, similar to the average fruit fly you see flying around overripe produce.
“Someone brought one in, and an entomologist saw it and said, ‘That’s not supposed to be here,’” Asakawa said.
Since the Japanese import was first identified, the vinegar fly has been found in raspberries and blackberries in the Santa Maria, Oxnard, and Watsonville areas, strawberries near Watsonville, and cherries near both Lodi and Hollister—though officials aren’t sure what other soft-skinned fruits are vulnerable.
The average, non-vinegar fruit fly takes advantage of the softening flesh of overripe fruit in which to lay its eggs. The vinegar fly, however, is tough enough to pierce the skin of ripe fruit for laying its eggs. The result is a squirming mass of larvae that feeds on the fruit.
Take a moment to get past the yuck factor.
Agriculture continues to be the county’s major producing industry. According to the Agricultural Commissioner’s Office’s crop report, 2008’s gross production was valued at $1,137,350,118. That amounts to a $34 million—or 3
percent increase—in gross value when compared to 2007’s figures. Those numbers also represent the third year in a row agriculture has surpassed the $1 billion benchmark.
With agriculture making such a giant impact on the county’s economy, it’s hard to imagine that it could be hurt by a pest as tiny as a worm, moth, beetle, or fruit fly—
but the county’s agriculture industry is just that vulnerable. That’s why the work of the state’s Department of Food and Agriculture and state and local farm bureaus is so valuable.
Asakawa said he’s asked all the time about how harmful such little pests can be.
“The produce/plant commodities are worth around $39 billion in the state of California,” he said. “We are the No. 1 agricultural state in the U.S.”
Asakawa explained that, in addition to the actual crops, hundreds of billions of dollars in marketing and related efforts could be impacted by pest damage.
“The financial damage and devastation it would do to the state of California, which already has problems, would be tremendous,” he said of a pest outbreak.
That’s why it was particularly alarming when the latest exotic pest—the vinegar fly—was discovered buzzing around the state in the spring.
A matter of control
Santa Barbara County Deputy Agricultural Commissioner Guy Tingos said vinegar flies are already here, and eradication is no longer an option. Now, it’s up to growers to control them. And growers will control them, because their livelihood depends on it, he said.
“The marketplace demands perfect fruit. Consumers just don’t like worms in their apples,” he said. “They don’t want holes. They don’t want bruises. They pick through it. [Commercial farmers] will be very careful.”
The fly has also just recently been detected, so not a lot of information is available yet. What inspectors do know is that such pests don’t get here themselves.
They come with people—not on their own accord, Asakawa said. That’s why traps are concentrated more in urban areas, with the number of traps varying according to population density.
Unannounced produce is the main culprit. Asakawa laid out a vivid example: A relative sends some fruit from out of the area. The receiver opens the box and says, “Oh, it’s got maggots,” and throws it outside in their backyard compost.
It’s as easy as that, he said.
The local agricultural commissioner will try to work with area growers to control the pests loosed on an unsuspecting public. Everyone
will work to minimize serious damage to the commodity the bugs infest.
Though the vinegar fly would likely be impossible to eradicate, authorities have been successful in their attempts to stamp out other pests. State and federal quarantines were recently lifted when officials eradicated the dreaded light brown apple moth. The infestation was small—only five moths found in Carpinteria—and it didn’t reach to Northern Santa Barbara County.
Native to Australia, the light brown apple moth is also found in New Zealand, the United Kingdom, and Hawaii. The leaf-rolling bug can hit more than 2,000 plant species, interfering with their photosynthesis. The result is a stunted or deformed seedling and significant damage to new growth.
Local officials had to wait through three of the moth’s life cycles with no further appearances before they could declare it eradicated. State and federal agriculture officials are currently developing sterile insect technology to combat light brown apple moth infestation, and a preliminary EIR is open for public comments.
The California Department of Food and Agriculture treated the quarantined area with pheromone-infused twist ties applied to host plants, trees, and fence posts.
Though the small Carpinteria infestation was quickly quashed, it did prompt a quarantine. State and federal regulations prohibit the movement of all nursery stock, all cut flowers, and all host fruits and vegetables and plant parts within or from quarantined areas unless the region is certified as free from the pest by an agricultural official, the goods were purchased at a retail outlet, or the plants in question were produced outside the area and are passing through in accordance with accepted safeguards.
In short, quarantines can severely cripple an area’s agricultural economy.
Like the light brown apple moth, the vinegar fly has the potential to be extremely destructive to the local agricultural landscape. Fortunately, the little egg-layer hasn’t triggered any quarantines yet—and it may not. Officials are simply waiting to see how effective local efforts will be at controlling the pest.
“It’s really hard to tell,” Tingos said. “It certainly has the capability of doing some damage, but it’s hard to know how long it’s been here. If it’s been here for some time, maybe it’s not going to be as bad as it has been in some places.”
Contact Arts Editor Shelly Cone at scone@santamariasun.com.
This article appears in Aug 20-27, 2009.