Pioneering Entomologist Battles for Biological Control in Agriculture

BY DAN IMHOFF

Farmer to Farmer, July 1994

To Everett Dietrick it's a bug eat bug world. For more than forty years he has been a devoted student of the natural enemy complex, and an ardent practitioner of biological controls in California agriculture. As a researcher for the U.C. Riverside Department of Biological Control from 1947-60, Dietrick participated in much of the pioneering work accomplished in beneficial insect management still in use today. Dietrick left the university in 1960 to launch a career in the private sector, co-founding Rincon Insectaries Inc., California's first commercial insectary. Since that time he has provided farmers with insects as well as farm management skills, in an effort to limit chemical usage to minimal applications of soft pesticides. Farmer to Farmer spoke to Everett Dietrick by phone at the Ventura office of Rincon-Vitova, where he serves as president and still puts in 50 hour work weeks, monitoring fields for such clients as Gallo and Pavich Farms, and selling generalist parasites and predators over the counter.

The parasitic wasp Hyposoter exigua lays its egg in a beet armyworm. The larva that hatches will grow inside the worm, killing it before it emerges.

How would you summarize your theory of biological control?

It is the regulation of pest populations by natural enemies, such as predators, parasites or pathogens that attack pests and compete for food and space with potential pest species. These organisms interact in specific ways that work in balance with nature.

There's a basic rule at work with biological controls: the more you hit nature with a pesticide, the harder it will come back at you. If you kill 95% of a given species, the remaining 5% will come back to haunt you. Resistance is the way nature fights back. A pesticide is good as long as it controls most of the insects. But when you get resistance and control failure, you're making money for the pesticide company, not the farmer.

Are there different types of biological control?

There are basically three: ( 1 ) classical, or the importation of exotic species and their establishment in new habitats; ( 2 ) augmentation of established species through direct manipulation of their populations, as by insectary mass production and periodic colonization; and ( 3 ) conservation through habitat management favorable to the survival and nurturing of naturally occurring predators, parasites and entomogenous pathogens.

Complexity seems to be at the heart of your theories of biological control. How would you describe this concept?

Complexity is what is necessary to biological control. This is why planting cover crops to increase diversity is so important. Cover crops and mulches can overcome the monocultures of modern farming. When you destroy diversity with plowing and cultivation to expose the soil to the sun, you destroy diversity and in crease dependency on pesticides.

Maximizing diversity of plants and minimizing interference from excessive pesticides, ants, dust and farming practices that destroy habitats for beneficials results in more effective biological control. The real proof for biological control lies in the many crops which are being marketed organically and are free of any pests or pesticide residues.

Do you know of any particular models where beneficial control has been effectively used over a long period of time?

When I first started my business in 1960, I modeled it after the Fillmore Citrus Protective District, in Ventura County. As far back as the 1940s, these farmers owned an insectary and hired entomologists to grow insects and monitor their orchards. They have 9,500 acres of citrus and have never sprayed more than an average of one time per acre per year in over half a century. When you have that much acreage you have many problems-ants, scale, road dust. They have a program of augmentation. Several species of beneficials are grown in the insectary and are regularly released to augment natural enemies. The idea is to nurture the biological control on these farms.

How does a farmer make the switch to biological controls?

The change comes when someone is dissatisfied. Either their spray program is too costly or ineffective or there are health problems. At that point the farmer needs a plan to back away. You don't quit tomorrow. If you don't have beneficial insects on your farm then you have to establish habitat and introduce them through insectary or field-harvested sources. It takes time but you can make these biological controls work on the farm.

What advice do you have to farmers interested in starting with biological controls?

You start with growing healthy plants in living soil. Then I encourage farmers to grow refugia. These are planned reservoirs of good bug species that can be maintained on a farm by fostering mulches and unsprayed cover crops- particularly legumes and many resident weeds. You strip cut the refugia to keep it young. Don't let it mature. Insects leave crops when they mature, looking for the next planting or host cycle. With refugia, a field always comes under biological control eventually and the spraying of hard pesticides can be reduced or eliminated. Begin with a portion of a field to get experience and find a PCA who is dedicated to your focus.

TYPES OF BIOLOGICAL CONTROL

Biological control comes in three forms:

(1) classical, or the importation of exotic species and their establishment in new habitats; (2) augmentation of established species through direct manipulation of their populations, as by insectary mass production and periodic colonization; and (3) conservation through habitat management favorable to the survival and nurturing of naturally occurring predators, parasites and entomogenous pathogens.

An adult green lacewing, Chrysoperla carnea. This general predator feeds on a wide variety of pests in the larva stage.

How exactly do these refugia work?

Borders of cover crop refugia attract and grow the numerous biological control systems needed to regulate the total complex of pests affecting all vegetable and field crops. No season is ever the same nor does any biological control system function the same in location or time. Constant monitoring and management of the system is required to make the most of beneficials.

Where does augmentation by releases of beneficials raised in insectaries come in?

Some augmentation is useful because insect cycles are worse some years than others. The only reliable sources for some beneficials are insectaries.

I read that you once referred to lacewing larvae as the DDT of the insect world. What are some of the most common lacewings?

There are many species of both green and brown lacewings. The most widely distributed species that insectaries produce is Cbysoperla carnea. This species is resistant to most pesticides, because the mother stock is taken from heavily sprayed farming areas. Brown lacewings are more active in winter and cool weather areas but are not cultured. Mass production of C. comanche and C. rufilabris are the only other ones that are marketed.

You worked with one of the founders of the Integrated Pest Management movement, Robert van den Bosch, at U.C. Riverside. What were some of your findings?

In 1953 1 began to assist Robert van den Bosch on a field crop survey. This was most exciting because up until then, biological control was thought to work only on tree crops or perennials. We were studying the "alfalfa/cotton complex." We found that you didn't have to spray cotton because the alfalfa insects would control cotton insects if they were next door to each other. As long as you strip cut the alfalfa, that is. The old equipment didn't move that fast and it took a long time to cut alfalfa. This slow gradual cutting of alfalfa kept the cotton pests in check in the alfalfa. The change to modern machinery has greatly increased the speed of work. Today you cut all the alfalfa in one week and all the pests go into the cotton seeking food. So you have to spray the cotton the next week. We reported our findings in 1960. This applied to many other crops, including vegetables.

Can you describe your early studies on citrus and avocados at the U.C. Riverside Research Station?

I spent five years with Dr. Paul DeBach researching citrus and avocados. Among many other studies, we were colonizing the vedalia beetle as a possible control for the cottony cushion scale. We found that repeat applications of DDT interfered with the vedalia ladybug. All we had to do was stop spraying DDT and we could manage the problem because DDT didn't kill the cottony cushion scale, but it did kill its natural predators. It was a classic success story of biological control. The vedalia beetle is still the natural enemy of choice today.

How would you direct current research efforts?

Our research should be concentrated on those pests for which we presently have no biological controls: black flea beetle, cucumber beetle, pink bollworm and fruit flies. There isn't the economic support to do this classical research. If the pink bollworm were brought under biological control you wouldn't have to spray cotton anymore. Of course that would mean a multi-million-dollar loss for the chemical industry.

What are some of the factors working against biological controls at the moment?

Fear. Difficulty in understanding complexity. Misinformation. A lack of faith in the system. I disagree with some organic farmers that healthy soil is the most important key to warding off pests. Of course healthy plants and healthy soil can ward off pests and disease. But what is most important in my mind is the ratio of good and bad bugs. This is so crucial. You want a high ratio of beneficials even with a low insect population. Fields are kept free of pest problems because of the complexity of biological systems. The concept may appear chaotic, but it is so simple.

How do you answer criticisms that using beneficial insects is a step back in time, where the farmer is unarmed against pests?

We're stepping way out in front because we know what is necessary now. Look at Europe where they are using very sophisticated biological control systems in greenhouses. They came to us in the 1950s to learn about biological control. Now we're the last to benefit from this knowledge.

I believe that somewhere in the world there is a natural enemy system that will manage insects and we need to spend a lot more time working with these complexes. Sooner or later the sprays are just not going to work and we're going to have to provide a refuge and learn to manage these insects with a minimum usage of soft pesticides that do not create more pest problems.

What are your visions for California agriculture?

My vision is for less and less spray. The only problem I see is fruit flies or the invasion of some other exotic pest and the consequences of eradication attempts. If the state tries to eradicate it with malathion they'll destroy all the progress we've made in a futile effort to satisfy a political problem. The world should learn to live with the fruit fly and find a way to keep it in check with biological controls and selective soft pesticides. With the $30 million annual eradication budget for the Medfly we could develop a focused search for biological controls and permanent solutions.

Prior to DDT most crop pests were controlled by natural enemies. Alfalfa hay was never sprayed and cotton only received occasional dusting for mites. I have witnessed the initial success and resulting failure of conventional pesticides to control resistant pests. The increasing numbers of new pest situations from insects which were previously secondary minor pests creates the need for an ever-increasing cycle of repeated applications of more and diverse sets of poisons. This pesticide treadmill destroys more and more predators and parasites, increasing the numbers of formerly minor pests, which are now becoming super-pests-resistant to all registered pesticides. Biotechnology is presently creating the next set of pesticides of genetically altered plants carrying resistance factors. Instead of seeking real biological control they seek to inflict more simplistic answers that will ultimately fail due to resistance development to these products. We are unsure of what other different problems will come from this technology.

General predators such as this big-eyed bug (Geocoris punctipes) feed on many pests in a wide variety of crops, in both adult and nymph stages.

At the same time myths about organic agriculture are perpetuated in a continuous propaganda campaign. They imply that organic yields are much lower and the cost of labor is much higher and the products are damaged. In short, we'll starve if we don't spray. I have witnessed many innovative organic production systems that are thriving throughout the world. We should be asking ourselves, "What steps do we have to take to get off total chemical systems and the pesticide treadmill? How long will it rake? What are the costs of the transition?"

The wonderful thing about biological control is that it's always progressing, always different. It is constantly fascinating to observe agriculture in the absence of pesticides. My goal is to eliminate the need for most broad-spectrum pesticides.

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Interview: Dr Everett Dietrick

Father of Commercial Insect Bio-Control Speaks Out

Acres USA, August 1996

It is now estimated that about a billion billion insects are alive at any given time on planet earth. This converts to a trillion kilograms of living matter; or slightly more than the weight of all the people in the world. Species number into the millions. Most of them do not even have a scientific name. It is a truism that insects can thrive without human beings, but humans cannot live without these small creatures.

We can be allowed to wonder why insects - installed some 300 million years ago - do not dominate the earth. Well, they do, and attempts to eradicate those lured on-scene by bad farming must be rated a prime example of man's stupidity.

Our interview subject this month is an American original. Some 50 years ago, he set up the first commercial insectary in the United States. He here explains his objectives and the reason for so few outposts of sanity in a poisoned world. Everett Dietrick is a product of California's education system, as he explains below His practical successes have made that state a leader in biological insect control, albeit not with enough success to sweep aside those who look to reductionist science in order to deal with ecology. A previous Acres U.S.A. Conference speaker; Deke Dietrick continues to expand both his message and client base as new insight and results prove out the role of bio-insect control in eco-agriculture.

ACRES U.S.A. Dr. Dietrick, we are told by science reporters that the tonnage of pesticides being used today is more than has ever been used before and still we have greater insect damage than ever before. How do you assess this information?

DIETRICK. Well, I think what the pesticide companies are selling is a drug in that it simplifies the environment by destroying the pests, or whatever it is that they are directing their attack against, but in the process they upset the whole system of things that manage insects. They create this problem by upsetting beneficial insect complexes that control other pests. The result is that secondary pests become major pests. I can remember - because I have been working in this for 50 years - when we only had a few pests that were serious, and they weren't nearly as serious as they are now. Of course, resistance is the key thing. You get good results for one or two years with a new chemical and then you get resistance. Now you have got secondary pests and the primary pests both bothering you. So you have really multiplied your problem by using the pesticides and, of course, the more you spray the more you have to spray.

ACRES U.S.A. In other words, we've offended the diversity that nature has installed out there to such an extent that we have really worsened the situation.

DIETRICK. Yes, .you get temporary benefits and in the long term disastrous consequences.

ACRES U.S.A. Is the idea behind propagating beneficial insects to reintroduce into the field the diversity that has been cancelled out by a lot of this chemical warfare?

DIETRICK. If it were that simple there would be a lot more insectaries, I suppose. It is really hard to grow the 200 insects that are all interrelating in one way or another to control houseflies, for instance. When DDT first came on the market it killed houseflies. I can remember several years when you never saw a housefly around a restaurant or anywhere. All the chicken ranches..., everybody was very happy, and then the housefly developed resistance. I just read an article the other day by Dr. G.P. Georghiou -he is supposed to be the resistance expert. He says there are over 500 insects now that are resistant to most major pesticides. The answer that they are giving for this is what they call integrated pest management (1PM). What they are referring to is integrated pesticide management. They've obfuscated the words, originally 1PM was established to do everything culturally and biologically to control pests and then spray only when necessary - that was the original 1PM. 1PM today is often rotating your pesticides and spraying a little more carefully.

ACRES U.S.A. Be sure you wear a rubber suit, a mask and gloves...?

DIETRICK. Absolutely, and, of course, you end up spraying more often. The more you simplify this environment to where it is one on one - you have a pest and you are putting a pesticide on for it - the more kinds of pests there are. Ultimately you'd spray every day. Of course, economically the farmer recognizes this, and then he either stops spraying and looks for another avenue or he goes broke. Many of them do go broke as a result of pesticide use.

ACRES U.S.A. But taking a different course over the last 50 years, you have discerned that there are vast benefits to insect releases. Even if you can't release a hundred species of insects, you can release one or two.

DIETRICK. Even if a farmer is buying only ladybugs -and we could argue whether that is a good product or not - if he is buying insects then he is not going to spray. Generally, if he doesn't spray then everything gets better.

ACRES U.S.A. The release really has its major effect be-cause it cancels out the use of the pesticides.

DIETRICK. If you live with a pest the things that are going to eat that pest come on to your farm. The only way you are going to keep them on your farm is to keep a tolerable level of that pest. One of the ways to sell pesticides originally was to create an artificial tolerance level, an economic threshold they call it. If you set the economic threshold too low then every field has to be sprayed, because every field gets that many insects. Every plant gets that many insects if you set the tolerance at that level. How do you scientifically set the tolerance at that level? It is easy if in your research and testing of the pesticide you work with farms that are all upset and have an extraordinary number of pests. Say you are studying lygus and so you call up the farm advisor and you say, "Well, I need a field with lygus in it so that I can test this pesticide." Then they will put on these replicated plots, and there is usually a check plot that they don't spray and, of course, that's an interfering plot. In other words, they call it biological control, but it is interfered with by all the other pesticides going around it.

ACRES U.S.A. Maybe they haven't heard of diffusion of air.

DIETRICK. The thing that happens there is that the threshold is set in a disturbed eco-system and therefore it is set too low. You can have these fields across the street from each other. One has got natural enemies on it and the other doesn't. In the one case the economic threshold is correct, because if you get the pest and it runs away real fast then you know that you have got to spray. Across the street the farmer gets the pests at the same time, but there is suppression there. There is biological suppression and the economic threshold is very different on a field that has natural enemies versus one that doesn't have them. How do you get natural enemies? You get them by living with -the pests. Now we have carried that a step further. We think of the cover crops and what we call insectary plants. Insects will stay on a farm if they have certain plants and also if these plants have certain pests. It is better to grow your insects on a cover crop which has unlimited tolerance for pests. It is a cover crop, a soil improvement process, not a market crop. We have developed what we call border strips, which are really set out to attract insects and grow beneficial insects that spill over onto the market crop and control the market crop. In case you had to spray your market crop you still have a reservoir of beneficials on your farm in those insectary border strips. They are really field insectaries. There isn't any way that private insectaries like ours are going to grow the insects necessary to take care of pests the way chemicals have in the past. It just doesn't work that way.

ACRES U.S.A. But you can inoculate the life process a little bit with your releases, can you not?

DIETRICK. Certain key species are important here, like in the case of the housefly. The parasites we grow for the housefly are the ones that control the last fly. They are very specific. If you have the 200 other insects that eat the eggs and larvae of the flies in the manure pile, and if you don't spray the manure pile, and then you attack the adult as an adulticide or as a bait without getting pesticide on the manure, then the release of the parasites will give you 95% control whereas otherwise you might only get about

80% control. You can go onto ranches that are absolutely clean of flies. They are not always that way because every spring there will be some flies. But where you release parasites, the flies will disappear a month sooner than they would otherwise.

ACRES U.S.A. What do the parasites attack?

DIETRICK. They get the pupae; they get the cocoons.

ACRES U.S.A. They get right to the foundation.

DIETRICK. This fly leaves the manure pile to the pupae, it wants to get away from the wet. We've got race tracks, all kinds of people who will normally do everything culturally that they can do to control flies - keep the manure down, and so forth. But they still have some fly pupae breeding there and releasing the parasites - they are like guided missiles that are seeking out their hosts, their prey, and laying eggs in them . It is a very good program that is more or less universally used. There a dozen insectaries like our putting these fly parasites out.

ACRES U.S.A. How do you get going in this business? How do you get started?

DIETRICK. I worked in the university in biological control at a very interesting time, having gotten out of the service early - I was ~ne of the first ones out after World War H. I went to Berkeley and happened to run into a friend of mine that I knew before the war, and he was in the U.S. Department of Agriculture. You see, during my college years I worked at the USDA part-time as an entomological aide, and it was these same people who were working up at Berkeley when I got out of the service. I got a job weekends growing insects for oriental fruit moths. It was a project that the Department of Biological Control at the University of California had where they were going to eradicate the recently arrived oriental fruit moths from California. They were going to do it by releasing massive numbers of a key parasite - Macrocentrus ancylivorus. We were growing these by the millions on a potato pest called the potato tumor moth. I got introduced to biological control by a staff of people that were unique in the world at the time. I think the University of California was the only university doing work with biological control. Even the USDA had very little work going on with it at this time. Hawaii had a very small program, but all of the other universities had a single department of entomology and they were headed by a chemical guys Of course, the way you market chemicals is that you make all of your entomologists think the only good bug is a dead bug. What we were doing was classical biological control in the sense that we were introducing exotic beneficials to attack the exotic pests that were coming into the environment. This was highly successful, and it is interesting that with all of the sterile male and all of the other things that go on, here was a case of releasing a key parasite of a new pest in massive numbers in the area where it had been detected, and this eradicated the insect. They didn't find it for years afterwards. So it is a successful case of using a biological control like a guided missile to seek and find these new exotic pests.

ACRES U.S.A. What went on with the screw worm eradication program?

DIETRICK. That was not even biological control - that was a mating disruption thing.

ACRES U.S.A. They sterilized the pests?

DIETRICK. They re-defined biological control to include all of that, including sterilization, mainly because money was being voted at the national level for biological control. However, the money was being intercepted and being put into the microbial things. The Bt, the Bacillus thuringiensis, was funded as a biological control. Really it was a biological chemical, not a biological control. It was a biological pesticide.

ACRES U.S.A. How do you define biological if you are not going to include sterilization and you are not going to include Bt?

DIETRICK. All of these things have been established to use the money that was originally voted to fund biological control without doing any biological control. We are not doing any more biological control today than we did 50 years ago. There is less money being spent on actual biological control. The other day a friend of mine in the USDA said that, in fact, there are all kinds of regulations being set so that you can't really do biological control any more. They are trying to control the movement of beneficial insects. Beneficial insects are now listed as pests in some categories. This is crazy because you have got to introduce beneficial insects if you get a new pest. Like codling moths - where did codling moths come from? Codling moths came from southern Russia, and we are just now getting around to bringing in a few parasites from southern Russia to get them established in codling moth here in California, particularly in walnuts and apples. There is a good opportunity for success here, but you can imagine what it would cost the chemical industry world wide if there were a good result - suppose the codling moths disappeared as a pest? - because that is essentially what happens when you have a successful biological control.

ACRES U.S.A. Would that have happened if the biological control had been used to battle the medfly?

DIETRICK. This is a political insect, the medfly. The medfly is a pest from the economic standpoint because these people have no tolerance for medflies. If you have them - if you detect a medfly in this state - then you have got to eradicate it.

ACRES U.S.A. Well, the late Dr. Albrecht referred to attempts to eradicate a weed or an insect as a monument to stupidity. Would you concur with that?

DIETRICK. I don't think that we have ever succeeded in eradicating anything. We have driven this particular pest down to a certain level, but there are a number of well-recognized people who assume that the medfly has not been eradicated even though they have driven it down below the detection point with these massive expenditures of dollars. Millions of dollars are being spent, and they could do a lot more with some of that money if they were looking for better natural enemies. You know, the medflies are just in the way, but we live with many fruit flies. A good example - when the oriental fruit fly came in to Hawaii, the research to keep it out of California was done in Hawaii. People from the university went to Hawaii and studied the thing. The chemicals completely failed with the fruit fly in the cases over there. It wasn't until the biological control that they had success, after bringing in a number of parasites. But they haven't found the proper ones for the medfly. Oriental fruit flies, melon flies - there are a whole array of flies that are in Hawaii. Some of their parasites are not very specific, they attack a lot of different fruit flies. But the key parasite for medfly would come from central Africa, and has, in fact, probably already been identified there by work done in Africa by an Italian entomologist back in 1935. Unfortunately, he was unsuccessful in bringing any of these parasites into Italy. You see, the medfly never got its name until it got to Italy without its natural enemies, where it became a problem. In Cameroon it is a non-pest. It is hard to find, and that's due to some 50 different insects that feed on it. Deciding which one is the key one will require some more work be done to studying it.

ACRES U.S.A. Now the Japanese beetle was a problem wasn't it, in California some years ago?

DIETRICK. This was a case in which the pest in question came from the east coast. Originally it came from Japan to the east coast. There were a couple of parasites brought in when they came from Japan. Actually, there was a bacterium that destroys it too. If you didn't have those three things working it would have devastated all the crops in the east. When it got to California, of course, it was a new pest. The eradication team, they have always been able to get money, money, money for eradication, and unfortunately many of the people in the Department of Agriculture support this goal of regulation rather than research. The Department of Agriculture has two divisions in it, the agricultural research division are the people whom I respect very much, because they do actual research.

ACRES U.S.A. But then you have the bureaucrat who is interested in legal and technical detail?

Diet RICK. That group, they are just regulators. They ~. biological control and they use sterile males, but

you see, that is a continuous expenditure of money. When you solve a problem with biological control it is solved forever - the parasites regulate the pests. It regulates with a low economic threshold. In other words, the pest can still be there and be a minor pest. In some cases, as with the vidalia beetle, it almost drives it to extinction. There is no case, however, of biological control completely extinguishing a species. It just drives it to a level at which you don't see it anymore.

ACRES U.S.A. In developing your insectary, you actually propagate a lot of insects and then you package them and move them out into the market for release by farmers, stables, and whatever?

DJ.~TRICK. Our business is inoculation, and today they are talking about inundation. Inundation would be enough to overcome the pest and drive it to a low economic threshold just by releasing the numbers. We have a couple of spray rigs on the market now where you are spraying beneficial insects. Lacewings can be sprayed on crops. This is all high-technology. This is maybe the first thing you can do, but the next step you want to take is to try to teach this farmer how to grow his own insects on his farm. Now that sounds stupid to most people in the bug business like myself, because you are working yourself out of a job. If you teach this farmer how to farm so that he doesn't have to buy insects, that doesn't make sense economically, but I always find that there are plenty of other customers I can succeed with in this regard. I can find another customer tomorrow.

ACRES U.S.A. Well, this is a little bit like hoping you are the only newspaper in town. You are really better off if there are other people in the publishing business because then you become a movement. If you are by yourself, you're just another nut. I suppose it would be the same if you were the only insectary in the country.

DIETRICK. Habitat management is the key to this success in farming. We need to farm with increased biodiversity. I don't know if you are aware of it or not, but the cutting edge of soil microorganism science right now is taking place at one to three places in the country. One of them is at Oregon State University, and there is a Dr. Elaine Ingham up there. She had given a talk at several of our EcoFarm conferences and I guess you would say that she is making a little sense from this reductionist science - a science in which you divide and divide, and you study everything and all of its parts, and it just doesn't lend itself to understanding what is going on in ecology. You reach a point where the complexity is so great that you can't make any sense out of the data; it's a nightmare. Most people just throw that kind of data out. They don't study organic farms for that reason - organic farms have too much complexity. You can't get statistical data, so to speak, that's supposed to be real science. Well, there is a real science that's above reductionist science. There is a good book on this called The Collapse of Chaos which you probably ought to read. You reach this point where all your complexity is such a nightmare that you have to step back and take another look at things. Now in regard to Dr. Ingham, she says that it isn't so important to know the name and identity of every microorganism in the soil. A teaspoon of good soil can have 100 million bacteria in it and maybe 700 or 800 different kinds. Another teaspoon just a short distance away may have different ones. It is a nightmare to try to understand all of that, but she says that she has reduced it down to function. For example, those bacteria that line up on the root hair have a similar function even though they might be different species. They still do the same thing. So you have got this system - and now you have got the ability to observe these things. She has equipment where she can take a meter of land and divide it into a million, and a root hair is three millionths of a meter and the bacteria line up on that and cover that root hair. They are a measure of activity. You see, the root hair doesn't have a cell wall. It is just a membrane that flows through the soil, and as it comes in contact with the soil bacteria or organic matter these bacteria are activated. Of course, this root hair is covered with these in a form of symbiosis. They are really beneficial bacteria and the plant is feeding those bacteria. It pumps 40% of its energy, in the form of carbohydrate, down into these root hairs from above ground. The photosynthesis creates the sugars and then they are pumped into these root hairs and feed them. At the next level - she calls these trophic levels -there is a set of other organisms, bacteria and amoeba and nematodes, and they feed on these bacteria that are right on the root hair. The carbon/nitrogen ratio of the primary bacteria on the root hair is like three to one, but the carbon/nitrogen ratio for the predatory group on those, they only need about 25 carbon to one nitrogen. So there is a lot of extra nitrogen.

ACRES U.S.A. When you speak of biological control in specific crops, you say that your best successes were in cotton?

DIETRICK. Yes, in cotton in the Coachella Valley. I had an opportunity to work with the only cotton gin in town and there were a lot of small farmers, about 2,000 acres total, and they had a cotton disaster in 1960. They picked a half a bale of cotton. Dibrom had come on the market [dibromochloropropane, banned in 1979. Dibrom was a new answer because of DDT resistance. You see, in the Coachella Valley they grow a lot of spring sweet corn, and when they stop growing corn all of these corn ear worms become cotton boll worms and they come roaring into the cotton as the corn goes out. Of course, they said, "Well DDT won't kill it anymore, but dibrom will." Well, dibrom didn't kill them and they ended up spraying the whole season, and, as a result, they ended up with half a bale of cotton. It is sort of what happened in south Texas last year with the eradication of the boll weevil.

ACRES U.S.A. They had a government-sponsored program for spraying the whole countryside.

DIETRICK. They created a beet armyworm problem, which could have been clearly predicted. You don't have to be very smart.

ACRES U.S.A. Well, most ecologists, well-trained ecologists, such as Edward 0. Wilson of Harvard University, seem to understand that spraying and poisoning is no way to control the diversity that is out there, and yet the public policy seems to pursue this line of reasoning.

DIETRICK. We are in the grips of the petroleum industry; they own our country.

ACRES U.S.A. You believe the pesticide industry owns our country?

DIETRICK. They market pesticides like cigarettes.

ACRES U.S.A. Yes. So you had very good success with cotton, what else?

DIETRICK. You know how you stop good success? You bring in a new pest. The pink boll worm comes to town and it doesn't have its natural enemies. There haven't been any really concerted efforts to try to find natural enemies for the pink boll worm. In spite of that, though, there has been some work. We know where the parasites are. I know where they are from my association with people in the university. You see the University of California is a wonderful place because it has a tremendous diversity, but the policies... You see, originally we had a department of biological control that was separate from the entomology department. The reason California was the birthplace of modem biological control was because they had separate funds and separate space. The Department of Biological Control was a statewide department of experts that were good at finding the natural enemies - exploration, importation into quarantine, study of mass production techniques, colonizing and establishing. I think we have some 30 different huge success stories of classical biological control in California. You couldn't grow citrus in California because of the vidalia beetle, that was the first one. Then there was this black scale, red scale and yellow scale. There are huge successes and every one of them is worth millions and millions of dollars to the farmers. They are there forever. We can grow citrus today with hardly any pesticides here in California, and it is due to the success of this Department of Biological Control. But it no longer exists. We now have the Department of Entomology. With the interest in economics, you have just one department, and it is supposed to be biological control, but the National Academy of Sciences now says that everything you do is biological control. So, you see, by changing the identification

ACRES U.S.A. They change the nomenclature and that erased the ability of that department to work?

DIETRICK. To the average person it makes sense. Why would you have two departments of entomology? The reason was that one was chemistry and the other was entomology.

ACRES U.S.A. And the chemistry won out? DIETRICK. The chemists won out.

ACRES U.S.A. What can you do for farmers who start seeing this connection between biodiversity and farming?

DIETRICK. Ijust met one yesterday and I'm going up to see him. He's got 4,000 acres of apples and peaches and I don't know what all in Cuyama Valley, which is about an hour and a half drive from here. He heard a talk I gave, and he wants to start making a transition. He is willing to drive me up there on Friday and we'll see what we can do. Now, what I will try to do is teach him, first of all, to change his soils. I would like to get him into restoring some organic matter to his soil. I assume he has probably been using herbicides.

ACRES U.S.A. He probably has a low mycorrhizal level if he's been doing that.

DIETRICK. He has destroyed everything. He's doing good on intravenous feeding. It's a very expensive way to farm and a very fragile way to farm. You can do it that way, just like you can live in the hospital forever on intravenous feeding, but it isn't a happy way to do it. It certainly isn't sustainable. What we should be doing is growing the way that everything was grown originally, with the nitrogen and carbon from the air. That's what is converted into food, and these plants do it for us. All we've got to do is understand it. But these plants, I read that they don't want fertilizers. They want sugar and carbons, and that's what some of these compost extracts are. One of the things that I have noticed - and I think Ingham has suggested as much in her work - those root hairs aren't interested in fertilizers. They are interested in sugars. They want to nurture these beneficial bacteria. When those bacteria are eaten in a biological control process, they kick back the nitrogen that feeds the plant and it is done at the root hair level. The mycorrhizae are involved here too because they are an extension of the root. The mycorrhizae fungi go out from 20 meters beyond the root zone and pull up moisture.

ACRES U.S.A. They have a sort of underground internet, don't they?

DIETRICK. Oh, it's an enormous internet. When you start citing the amount of mycelium there is in a square inch - say a leaf that is decomposing - it gets to be miles of mycelium because they are so small. It is a very good protein if you want to wash it off and eat it.

ACRES U.S.A. Have you been able to use your form of bio-control in rice?

DIETRICK. There is one rice grower that never sprays up in the Sacramento Valley. He grows organic rice. I think there are tadpole shrimp, there's - every one of these crops has its unique set of problems - there are some general problems in the world but they are pretty unique wherever you are. The International Rice Institute, I know, has done a lot with biological control throughout the world. They got into pesticides, and they got plant hoppers that were just killing them. They found out they could keep the spiders, that spiders were their primary management tool, and they worked out ecological systems where they keep these spiders in the environment in between crops. The United Nations has done a lot of work with nce.

ACRES U.S.A. How many different insects do you propagate at your establishment?

DIETRICK. Oh, we propagate maybe 20 different insects here.

ACRES U.S.A. And about how many different crops would those be useful for?

DIETRICK. The ones that we grow are useful in probably over 50 crops. The ones we grow are generalists. We need a market year-round and we still don't have a market in the wintertime, though we are getting into greenhouses and indoor plantings and backyard gardens and people's houses. We've got packages of insects we can send for all kinds of things. We market everybody's insects. We can get you any kind of beneficial insect on the market. We can package it for you or have it drop shipped to you. More and more people are doing it. Artificial environments like greenhouses and places like them are where the insectaries really play a role because they are growing high-income crops and they can afford to pay the price. It is more like an insectary. You can learn to grow these things in your greenhouse and it is only a matter of making small adjustments to the systems that they are already using. There are some fairly successful ones now. We are working in that field and that's a year-round market. You see, our costs are people. This is labor-intensive work and marketing is the shipment of the product and it's difficult.

ACRES U.S.A. Well, how does anyone get a hold of you? Let's say a grower reads this report?

DIETRICK. We're pretty busy, by being the first one and starting in this as the only one really in private enterprise, we can't take care of everybody. But we can provide people with information. I talk to a lot of people and mostly they don't have to do much different from what they are already doing. This getting off of pesticides is basically the number one thing and so is the desire to do so. It is better not to do that from the standpoint of being bankrupt, it is better to do it by choice.

ACRES U.S.A. Do it from a position of some strength?

DIETRICK. Basically I find that if they stop the hard pesticides completely - hard meaning the broad-specturn ones that kill all of the insects - they have a good start.

ACRES U.S.A. For hands-on type of people, are you willing to counsel or help people who want to maybe produce one or two insects?

DIETRICK. We do what we can over the phone. I don't run an identification service and generally you have to find out what the problem is before you can know what to do. People call and say, "I've got a green-looking bug that's about an inch long." With the millions of kinds of insects there are, we have to ask them a lot of questions about the bug - the kinds of crops it is affecting - and eventually you've identified pretty well what it is and then you know if you can do something for them or not. But that takes a lot of time. I think all of these things are basically nutritional problems. I think you were probably the first one to recognize that. Organic farmers don't have the problems that chemical farmers have. Philip Callahan is a physicist, and he speaks the language of physics. The chemists speak the language of chemistry. The entomologists speak the language of entomologists. I've heard many people who are cross-trained and speak all of the languages that we are talking about. That's what comes out in this book, The Collapse of Chaos: Discovering Simplicity in a Complex World. It's by Jack Cohen and Ian Stewart. They are a couple of English guys and they got onto the subject of chaos. I think a key example is taking this complexity of soil organisms and reducing it to five or so trophic levels. In other words, you take the complexity and you say, well, function is the key thing here and not identity - whether it is Smith or Jones or Brown or somebody else. It doesn't matter which one of these microorganisms it is, if they have the same function. Now you only have five things to deal with and you can take aliquots of soil and you can sample for living organisms. Ingham does a bio-assay of the life in the soil. You want to take your sample from the top inches of soil and it has to be at a time of year when the soil is moist and the maximum growth is taking place. You take it from the most productive part and compare it with the least productive part of your farm. You can see what systems are missing and you can see the relative numbers. She's got data on grassland, on pine trees, if they are interested on this clear-cutting. In Oregon they have tried and tried to repopulate these old forests after they clear cut them, and they find that forests are fungal dominated. They are dominated by fungi systems and you can't restore those. Anytime you plant trees back into this ground after it has been bare for a while you can't get the trees to grow. They won't grow without the fungi.

ACRES U.S.A. It is several times worse in the tropics.

DIETRICK. Yes, because these are temperate forests. We are destroying them right and left. Now the other book that I am really interested in is one Dr. Ingham listed as a basic text book. It is called, Soil Ecology and is by Ken Kiliham, whom I think is another Englishman. You know, the English have been doing work in organics for a lot longer than we have.

ACRES U.S.A. Well, the bottom line to everything you have been saying then seems to be that it has to start with the soil, and once you have the soil moving in the right direction then you can give it a little bit of an assist.

DIETRICK. Yes. And you do it with a continuous flow of application of composts and compost teas, and you make your compost from the widest variety of materials. You know Dr. Ingham can use the same sampling in different composts to see if all the systems are there and if they are there in one number better than another number. She's got about 3540,000 samples now in her data base. This is really new. This is the cutting edge and you probably ought to talk to her. Our insectary is unique in that we sell key insects that are useful. Lacewings, for example, are generally useful in just about any situation. They are a general predator. Ladybugs are good, but the problem with the ladybugs is that they are collected in the mountains and they don't always have the same quality.

ACRES U.S.A. What is your biggest item?

DIETRICK. I think trichogramma more than anything. The way we grow these, you not only have to grow the predator or the parasite, you also have to grow the host or a surrogate host. In this case we use a green moth. We grow tons of barley to grow green moths and then we use those eggs to feed the trichogramma - the fresh ones -and then we can freeze them and feed them to the lacewings. I can grow the food insect year round and freeze it and utilize it at peak times of the year. It is the economics of having the product at the right time - this is over-the-counter sale. I don't have anybody paying me in advance. There is no support for this thing.

ACRES U.S.A. You have to make it the hard way in the market.

DIETRICK. This is just like growing tomatoes. We have competition with all these other insectaries.

ACRES U.S.A. Well, you always have a little leg up if you are first, and you deserve recognition for being first.

DIETRICK. I think what we are doing is expanding, getting new products. Most of the people who run these other insectaries who work here have visited. I have always kept an open house for visitors mainly because my goal has been to solve some of these problems. If I wanted to get rich I would have gone into selling insecticides. That's like dope, you get people hooked on it and they keep coming back.

Everett J. "Deke" Dietrick is founding president of Rincon-Vitova Insectaries, Inc., D-Vac Company, and the Everett J. Dietrick institute for Applied Insect Ecology For more information call (805) 643-5407, or write to bugnet@rinconvitova.com

Winning Respect for Biological Pest Control

An Interview with Everett Dietrick

http://www.seasonalchef.com/dietrick.htm not active website

Mark Thompson

Seasonal Chef

P.O. Box 4039

Culver City, CA 90231

tel. 310/558-8466

e-mail: markthomp@yahoo.com

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

'I don’t want to perpetuate the myth that you can spray with insects and get the same results that you get with pesticides. It doesn’t work that way.'

Dietrick picks up a load of scale-infested squash, which he uses to incubate 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 couldn’t have been happier when he stumbled into a job sweeping up and doing other odd jobs at the U.S. Department of Agriculture’s 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 department’s 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 employer’s 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 world’s first commercial insectary.

He is a pragmatist, willing to acknowledge that some chemical pesticides work so well that it doesn’t 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 Gallo’s 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 didn’t 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 couldn’t find any. There were hardly any left. We looked in cities where it was warmer, where they hadn’t 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 didn’t get reported at the time. I don’t 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 wasn’t 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. That’s 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, ‘I’m 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. It’s not even a conspiracy. It’s just that these people think alike. It you think alike, you don’t 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 wasn’t 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 wasn’t 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 couldn’t show it to you. They couldn’t 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. It’s better than selling dope. There’s a lot more money it.

My program included advice. I used insects that were in the field. Mostly you’re holding the farmers hand, because he’s worried. But it’s 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 didn’t want to perpetuate the myth that you can spray with insects and get the same results that you get with pesticides. It doesn’t work that way. You can inoculate with beneficial insects. You can augment those that are in the field. But you’ve got to learn to grow them. You’ve got to bring back the complexity, introduce cover crops and crop rotations. It’s 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 we’re realizing that we can’t live with all of these chemicals. We’re going to have to depend on biology. Stephen Gould, a biologist at Harvard, says we’re probably so dependent on microorganisms -- the fungi, the bacteria, all the things that are in the environment -- that we can’t 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. We’re 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 you’re 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. It’s addictive.

Now we’re getting new pests all the time. It’s obvious we’re going to get more pests because there’s more travel. But I also believe we’re getting more pests because of scorched earth agriculture. It’s a monoculture out there. There’s mulch but it’s not the same as having a cover crop. There’s not much diversity out there, no alternative hosts. Farmers have been taught to farm this way because they say it saves water. Well it doesn’t save water. Most of the water is saved in the body of microorganisms. If you don’t have microorganisms, you’ve got sand and rock out there and it doesn’t hold water.

The organic farmer already knows that. He doesn’t have to understand it because he believes it. If you feed your microorganisms, they’ll feed your plants.

It’s so straightforward and simple it’s amazing they were able to pull it off. Yet it’s 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. That’s 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 don’t even care if it’s a little subterfuge. It’s so important.

SEASONAL CHEF: Is there any role for chemicals in farming, in your opinion?

There’s no denying the usefulness of chemicals. To me the awful thing about it is that we’ve 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 wouldn’t want the strongest application. You don’t 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 hadn’t 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. It’s 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. It’s more of a labor of love for me. If I could teach the whole world so they wouldn’t 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 that’s not a problem. The chemical industry is constantly creating new customers for us every day.