Biological Pest Control
An Interview with
One recent afternoon in his office at the Rincon-Vitova Insectaries Inc. outside of Ventura, Everett Dietrick had an unusual centerpiece on his desk. It was a grapefruit that he had picked up at the Saturday morning farmers market in Ventura a few days earlier. The odd thing about the piece of fruit was that Dietrick was keeping it in a mesh-topped container in the company of several small, black Aphytis melinus beetles. The insects were roaming over the surface of the grapefruit, focusing their attention on splotchy brown patches of scale, laying their eggs in the pest.
Dietrick admires a box full of writhing
housefly larvae that will host the
next generation of beneficial insects
| Within a few days, the beetle larvae would hatch,
killing the scale. Dietrick planned to take the fruit
back to the farmer so he could see for himself how the
beetle larvae were wreaking havoc with a pest that the
farmer feared was about to run amok in his orchard.
Dietrick, who grew up surrounded by lemon groves in pre-war East Whittier, says he knew by the time he was 10 that he wanted to become an entomologist. So later, in Whittier College on a football scholarship, he couldnt have been happier when he stumbled into a job sweeping up and doing other odd jobs at the U.S. Department of Agricultures Citrus Insect Investigations and Plant Quarantine Laboratory on the edge of town. Dietrick was so dedicated to the work that he was quickly promoted to more important jobs, such as tediously counting scales on citrus trees before and after treatments of cyanide gas. The studies showed that some of the insects always escaped death to reinfest the trees with progeny a little more resistant to cyanide.
After a stint in the Coast Guard during World War II, Dietrick started graduate school in the entomology department at the University of California in Berkeley. He ended up with a job at the departments newly formed biological control laboratory where he worked for many of the legendary pioneers in the new field. The scientists he worked for included Paul DeBach, who wrote one of the first text books on biological control and was one of the first to demonstrate the devastating impact of DDT on beneficial insects, and Robert van den Bosch, who wrote a scathing denunciation of his employers entanglements with the chemical industry called "The Pesticide Conspiracy."
Some of both the educator and the agitator rubbed off on Dietrick, who in 1950 started raising beneficial insects in his garage in Riverside, a venture that was the worlds first commercial insectary.
He is a pragmatist, willing to acknowledge that some chemical pesticides work so well that it doesnt make sense not to make sparing use of them. But the Santa Paula Valley, where Rincon-Vitova is located, offers strong proof that a great deal of the spraying on many farms is unnecessary. the nearby Fillmore Citrus Protective District has had its own insectary since the 1950s, and has averaged only one spray per acre per year for all 10,000 acres in the district ever since, says Dietrick.
At Rincon-Vitova, which Dietrick co-founded in 1960, he and his employees breed green lacewings, Aphytis melinus beetles and a number of other beneficial insects and ships them to farmers throughout the world. Dietrick also offers pest-control consulting services to farms include the Gallos extensive vineyards. The company now has many competitors, a number of them formed by people who used to work for Dietrick. He takes it as a welcome sign that the work that earned him and his mentors a lot of grief in the early days is now gaining wide acceptance.
Seasonal Chef has interviewed Dietrick several times over the last several years. Here are excerpts from those interviews.
SEASONAL CHEF: What was one of your first success stories with biological control of a pest?
DIETRICK: The first biological control program in California was in the 1880s with the Vidalia beetle for citrus scale. That was forgotten after World War II when DDT came along. But the DDT killed all the beneficial insects and right away created this holocaust of pests.
When I started working for the University of California in February 1947, a wide area of citrus was just like a snowstorm with cottony cushion scale. Some of those orchards didnt produce for two years, they were so infested. I spent half of my time looking for Vidalia beetles and restoring them to the Central Valley. We spent days up their looking for reservoirs of Vidalia beetles. But at first we couldnt find any. There were hardly any left. We looked in cities where it was warmer, where they hadnt sprayed. We found them on ornamental plants. We collected about 50,000 beetles and released them in the valley, a reenactment of the original biological control program, the saving of citrus in 1889. This didnt get reported at the time. I dont know why but it took 20 years to publish the work that we did with evaluating the effects of DDT on the beneficial insects in citrus.
SEASONAL CHEF: One of your colleagues from that time, Robert van den Bosch, wrote in his book, "The Pesticide Conspiracy," that he was reviled for his pioneering work on biological control. Did you ever experience hostility?
DIETRICK: The first project that made some people mad was with biological control of the alfalfa aphid. The infestation began just east of Brawley. Probably somebody brought an infested bale of hay from the Middle East. The aphid just took off and started to spread. Pretty soon, we heard that farmers were spraying three times per cutting.
Well, they had a problem. Clearly the pesticide wasnt working. After you devastate the area with chemicals, the pest population explodes on you. The last thing they do is call in biological control.
We got $100,000 for a three-year project. We started to grow alfalfa in greenhouses. We found parasites right away in the Middle East. We found three parasites that attacked the aphids. We released them and soon we had 10 or 12 fields with well established parasites. We had field days at the research station and we would give farmers a stalk with parasitized aphids, tell them to take it home and put it in their field.
In about one year, the $9 million parathion spray program on alfalfa dropped to less than half a million. Thats kind of when the crap started to hit the fan. I remember one day when a chemical company development guy came in, and he said, Im going to get your job! But they never did acknowledge that the biological control was responsible. It was typical of the way they have downplayed biological control. Its not even a conspiracy. Its just that these people think alike. It you think alike, you dont have to conspire.
There was just no way to stop the marketing steamroller that took place with DDT after World War II. The chemical industry realized they had these powerful tools that were just waiting to be exploited. And it wasnt long before the marketing people took over the chemical industry. The entomologists lost control of it. And the companies began hawking chemicals like they were drugs. They were enormously successful for a while.
SEASONAL CHEF: When you first went into business as a biological pest control adviser in 1960, were there any customers for your service?
DIETRICK: It wasnt easy. If the university tells the farmer to spray and the chemical company tells him to spray and the county agent tells him to spray and nobody tells him not to spray, see how easy it is to spray. But I walked in the fields every day, so I would tell the farmer, ask them to show you the pest that needs to be sprayed. Nine times out of 10, they couldnt show it to you. They couldnt even remember where they saw it. Maybe it was a fictitious bunch of baloney that they used to try to panic the grower. If they could get the first spray on, they could spray him five or six more times. Not for the same pest but for another pest that they created the environment for. Its better than selling dope. Theres a lot more money it.
My program included advice. I used insects that were in the field. Mostly youre holding the farmers hand, because hes worried. But its no different than a doctor who says go home and drink a glass of water and take an aspirin. A placebo. I knew that his immune system was going to take care of him. I think all farms have sort of an immune system. Like any immune system there are little areas of upset that take place.
SEASONAL CHEF: Were your first clients happy with the results?
DIETRICK: It takes time to get results. I didnt want to perpetuate the myth that you can spray with insects and get the same results that you get with pesticides. It doesnt work that way. You can inoculate with beneficial insects. You can augment those that are in the field. But youve got to learn to grow them. Youve got to bring back the complexity, introduce cover crops and crop rotations. Its amazing how quickly nature will heal itself. One of our main approaches right now is to provide refuge cover cropping to attract insects. The more insects, the better the control. Pretty soon you work yourself out of job. The insects are doing it for you.
SEASONAL CHEF: Is the climate for biological control more favorable now?
DIETRICK: Now were realizing that we cant live with all of these chemicals. Were going to have to depend on biology. Stephen Gould, a biologist at Harvard, says were probably so dependent on microorganisms -- the fungi, the bacteria, all the things that are in the environment -- that we cant do without them. Ten percent of our body is microorganisms that are protecting us. In a teaspoon of soil there are 100 million bacteria, maybe 700 kinds. Were just beginning to understand this complexity. Just in the last 10 years there has been such a breakthrough in understanding the way things operate when youre not depending on farm chemicals. Farm chemicals kill off the microorganisms and then try to replace them. But the more you use them, the more you have to use. Its addictive.
Now were getting new pests all the time. Its obvious were going to get more pests because theres more travel. But I also believe were getting more pests because of scorched earth agriculture. Its a monoculture out there. Theres mulch but its not the same as having a cover crop. Theres not much diversity out there, no alternative hosts. Farmers have been taught to farm this way because they say it saves water. Well it doesnt save water. Most of the water is saved in the body of microorganisms. If you dont have microorganisms, youve got sand and rock out there and it doesnt hold water.
The organic farmer already knows that. He doesnt have to understand it because he believes it. If you feed your microorganisms, theyll feed your plants.
Its so straightforward and simple its amazing they were able to pull it off. Yet its taken me a lifetime to understand it. And I know there are people in the chemical industry who are smart enough to have programmed it. Thats what really bothers me.
The way to change things is to pull the rug out from under the chemical industry teaching farmers how to farm. Organic farmers are way ahead on that. I would do anything to try to teach a farmer how to back away from chemicals. I dont even care if its a little subterfuge. Its so important.
SEASONAL CHEF: Is there any role for chemicals in farming, in your opinion?
Theres no denying the usefulness of chemicals. To me the awful thing about it is that weve destroyed them all through marketing them like cigarettes rather than using them to manage insects, to help your biological control. You would want a selective pesticide. You wouldnt want the strongest application. You dont want the "if one pound is enough than five pounds is better" approach. It would be nice to utilize some of these products, if they hadnt been abused.
I think the organic label both hurts and help. It hurts in that there are some little things that the organic farmers feel uncomfortable about doing that might be useful to them, particularly if they only have to do it once to save their crop, to keep the wolf away from the door. Its crazy not to.
SEASONAL CHEF: How is business at Rincon-Vitova these days?
DIETRICK: I personally have not been in this business to get rich. Its more of a labor of love for me. If I could teach the whole world so they wouldnt have to use pesticides, I could find something else to do. What we sell is worth the money, but it is not habit forming. So we have to depend on constantly getting new customers. But thats not a problem. The chemical industry is constantly creating new customers for us every day.
Copyright 1997 Seasonal Chef