Everett Dietrick - Biological Control Pioneer

Reprinted by permission from

The IPM Practitioner, V 17, No 1, Jan 1995

By Tanya Drlik

During this century, the U.S. has been home to a hardy band of pioneers in the science of biological control. It is ironic that at a time when we need biological control more than ever, the infrastructure that supported these pioneers is being allowed to crumble. For instance, the University of California, which was at the forefront of post-World War H biocontrol successes, has downsized the Division of Biological Control at Berkeley, and now only four faculty members work there. Although UC Berkeley has a modest biological control lab at the Kearny Agricultural Center in Parlier, and biological control activities are underway at other campuses, classical biological control research is suffering in the reorganization. Overall funding may actually be increasing, but money is being diverted to approaches based on biotechnology and genetic engineering.

Also, Federal agencies are taking a stronger role than before in regulation of classical biological control For instance, the U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA/APHIS) requires a costly environmental assessment before non-indigenous beneficial organisms can be released. A number of other federal, state, or even county agencies have regulations that must be satisfied.

The great men of biological control are retiring without being replaced, and their wisdom is slowly being lost. Everett Dietrick is one of the greats. At the IPM Practitioner we have been honored to know him, and he has been inspiration to us. In this article we attempt to capture his philosophy and some of his experiences for our readers. -The Editors, IPM Practitioner

Tanya Drlik is an IPM specialist with the Bio-Integral Resource Center.

Stories about biological control of insects in California agriculture come pouring out of Everett Dietrick in a torrent that leaves the listener reeling. At 74, the energetic "Deke" still monitors fields for large clients such as Gallo and works 50-hour weeks in the Ventura office of Rincon-Vitova, the insectary he co-founded. His 55 years of experience in the field make him a living encyclopedia of biological pest control in this country. "I love my job and I've had an exciting life," he says. "I could have gone to medical school, I guess, but I'm sure glad I didn't."

Everett Dietrick and his wife Gwyn at the office of Rincon-Vitova Insectaries

Everett J. Dietrick was born on a Nebraska farm and moved to California in 1925 when he was five years old. His interest in insects began in his childhood and by the end of high school he had an extensive collection. After graduating from Whittier High School, he attended Whittier College on a football scholarship, majoring in biology and minoring in chemistry. There, quite by accident, he got a job working part-time at the USDA Citrus Insect Investigations and Plant Quarantine Laboratory attached to the Whittier campus. He earned 40 cents an hour sweeping up and keeping trucks fueled.

Because of his keen interest in entomology and laboratory work, Dietrick was promoted the following year. He assisted A.W. Cressman, who was working on red scale in citrus. Cressman exposed him to entomological research tasks ranging from insect collection and counting to statistical analysis. Dietrick ruefully recalls, "I think I counted more red scale than anybody in history."

In those days, fumigating with cyanide was the main form of pest control in citrus. "They covered individual trees with a canvas tent, took a lump of sodium cyanide, dropped it into acid, threw it in and ran. Even though they got 80% control that way with very little residue, they weren't satisfied. They eventually got gas-tight tents so they could get 90% kill. With that kind of pressure on the population they began to see resistance. Eventually oil sprays came into use because of the resistance problems."

Ensign Dietrick of the U. S. Coast Guard

After graduating from Whittier College and while waiting to go into Coast Guard Officer Training, Dietrick found a summer job working as an insect scout, spray nozzelman and cyanide fumigation helper for the joint USDA/California State Department of Agriculture Hall Scale Eradication Project. Ernest "Stubby" Green was a crew chief on the project. Dietrick and Green became friends and later U.S. Coast Guard officers.

After the war, Dietrick started graduate school in entomology at the University of California at Berkeley. Chlorinated hydrocarbon pesticides were just beginning to be marketed then. "I remember a class I had at Berkeley where we were supposed to accumulate labels from insecticides. The idea was that these labels would be useful references for a lifetime. Of course, some of those materials only lasted a couple of years before they were worthless because of insect resistance."

UC's Gill Tract

Dietrick's contacts at USDA and his experience at Whittier got him a job at the newly formed biological control laboratory at the Gill Tract in Albany near Berkeley where he assisted Glenn Finney in mass-rearing Macrocentrus ancylivorus, a parasitoid of the oriental fruit moth, Grapholitha molesta. Inundative releases of this parasitoid were made from 1944 through 1946 in the peach growing areas of California, and by 1947, pest populations were so low it was hard to find a single moth. This obvious success notwithstanding, in 1954 when California experienced the first serious outbreak of oriental fruit moth, the authorities apparently didn't even consider using natural enemies, perhaps because they were convinced of the efficacy of the new "wonder" pesticides.

Dietrick was intrigued by the science of biological control, but as there were no courses on the subject offered at U.C. Berkeley, or anywhere in the country, he gleaned information from the many biological control experts who worked at the Gill Tract and the scientists who came to visit. As a graduate student he got to know Professor Harry Smith, who was head of the statewide U.C. Department of Biological Control. "My time at the Gill Tract," recalls Dietrick, "was a turning point in my life, and I actively sought the experience from on-the-job training in order to learn everything that I could about biological control by natural enemies."

DeBach and the Red Scale Project

In February of 1947, Dietrick moved to Southern California to work as senior lab technician for Paul DeBach at the Department of Biological Control at U.C. Riverside Citrus Experiment Station. DeBach, who wrote a pioneering textbook on biological control, was in charge of a 5-year project to study the classical biological control of red scale. Red scale biocontrol efforts started in 1889, but the two most important natural enemies were not successfully introduced until 1948 and 1957. The problems in the intervening 50 years were due mainly to lack of ecological data on the pest and its natural enemies, and to insect misidentifications.

Dietrick (center) is shown with Paul DeBach on the left, and Jack Dudley on the right at Laguna Beach, CA in 1950 after a skin diving competition.

Dietrick and DeBach evaluated the effectiveness of the red scale natural enemy complex in citrus and avocado orchards. Biological control scientists had recognized immediately that the new broad-spectrum insecticides were more toxic to natural enemies than to insect pests, and DeBach used this selective toxicity to his advantage. By applying DDT to individual trees in a manner that killed most of the beneficial insects while doing little harm to the pests, he could directly study the effects of natural enemies on the pest population. In addition, he documented that through pesticide use a pest problem could be created where there had been none before.

The red scale project also researched the effects of ants on citrus pests. "Our work led us to the conclusion that high populations of honey-dew seeking ants could be as devastating to biological control as DDT," says Dietrick. Even hand removal of beneficial insects could disrupt the system when done continuously. Eventually, DeBach and Dietrick came to the conclusion we take for granted today: climate, weather, road dust, ants and broad spectrum pesticides can all be significant impediments to successful biological control.

The Insectary Idea

Dietrick says his idea for a commercial insectary came from listening to Paul DeBach and Harry Smith during trips they all made during the red scale project. In the 1950s the insectaries in this country were all funded by federal, state or county governments or by farmer cooperatives or pest control districts. The Fillmore Citrus Protective District (FCPD) had been formed to eradicate citrus pests, but an insectary to produce beneficial insects was added when the impracticality of eradication became evident.

DeBach's studies showed that biological control in citrus was economical. Working with growers and the FCPD, he and his colleagues soon began developing a pest management program for citrus. Dietrick recalls that "Howard Lorbeer, manager of the FCPD, in particular led us to the conclusion that pest management by natural enemies served the farmer better when supported by augmentative releases of key beneficials and by ant management."

Around 1946, Ray F. Smith of the Division of Entomology at UC Berkeley had developed the idea of "supervised control" based on work he had done with A.E. Michelbacher on the role of the parasitoid Apantales medicaginis in controlling the alfalfa caterpillar. Supervised control involved routinely monitoring pests and natural enemies in the field and prescribing to the farmer what, if any, control was needed. This concept eventually evolved into integrated pest management.

Paul DeBach and his colleagues developed a supervised biological control program for citrus, but although they tried very hard to generate support for their ideas, they found little public or private interest. The FCPD did, however, continue to benefit from their work, Dietrick says, "by averaging only one spray per acre per year for over fifty years on all of their nearly 10 thousand acres. Their fruit was chosen for overseas shipment because of superior quality, lack of fruit rots due to oil spray deposits and the implied lack of pesticide residues. These experiences helped to form the basis for the idea of integrated pest management (IPM)."

First Commercial Insectary

Dietrick started his first commercial insectary secretly in his garage in Riverside in 1950. "I was naively ready to sell a pest management program similar to [the program used by] FCPD to any farmers wherever they were located. I began growing Aphytis 'A' [Aphytis lignanensis from China], a new importation that appeared to be effectively controlling red scale in the hot, dry inland valley climate of Riverside. My first and only customer was Mr. Stover, a Board Director of a large citrus production company. He used the parasites on a 20-acre block of his lemons." This area was heavily mulched and irrigated by overhead sprinklers which fostered a suitable habitat for beneficials. The habitat modification along with the deterrent effects of the mulch on the ant population allowed for satisfactory biological control of all pests except the California red scale, which Dietrick thought could be controlled by augmentative releases of Aphytis.

Stubby Green, Dietrick's friend from the Hall Scale Eradication Project, also became interested in a commercial insectary. "I used to stay at Stubby's house when I was working in Ventura and Santa Barbara counties. Stubby and Doug Green owned Green's Pest Control and Stubby had money and off-season time to invest in a commercial insectary. We thought that the lack of any market for beneficial insects was solved when nearly all county-supported insectaries were closed due to budget restrictions. The conventional thought was that synthetic, broad-spectrum pesticides had put an end to pest problems forever."

Formation of Rincon

The Green brothers formed Rincon Insectary in 1951 to produce Cryptolaemus montrouzieri, "Crypts" for short, a ladybird beetle that was imported at the end of the 19th century to control mealybugs in citrus. Dietrick offered support in the form of advice and encouragement while continuing his red scale work with the University. Unfortunately, there was little market for their Crypts because farmers were as yet unwilling to pay for beneficials they had previously obtained for free. Dietrick's garage insectary was short-lived because he had to discontinue his Aphytis rearing in order to keep his U.C. job. The Rincon Insectary and Dietrick's covert operation in his garage were the first commercial insectaries in the world.

Expanded Biological Control

When Harry Smith retired, Curtis Clausen became head of the U.C. Department of Biological Control, and took the opportunity to expand biocontrol research into many crops other than citrus. The biological control pioneer Robert van den Bosch was selected to head a new project entitled "Survey of Biological Control of Vegetable and Field Crops." In 1953 Dietrick left the red scale project to work with van den Bosch. Dietrick recalls that "before van den Bosch arrived on the scene, no one really believed that biological control could work in field crops." Van den Bosch was to become one of the most articulate and outspoken proponents of biological control, and a hot-blooded critic of what he called "the pesticide treadmill."

Dietrick worked until the summer of 1960 on field crops. "I was captivated by our research in alfalfa, cotton, sugar beets, grains and investigations into organically grown vegetables. It was a time when the Department of Biological Control was administered statewide with its own space and a budget free from many of the chemical advocate pressures that dominated research at most universities. Space and money control the direction of research. While the world was driven into pesticide addiction, we were free to examine the potential for biological control of pests of food and fiber without political restraints. This was an unsurpassed productive period for research in biological control and unfortunately few farmers or political leaders in agriculture were ever aware of the accomplishments."

Alfalfa as an Insectary Crop

From his work in field crops Dietrick began to gain an appreciation for the role that unsprayed alfalfa and by extrapolation, cover crops, played in agricultural biological control. "We had intensively sampled unsprayed cotton crops grown by the De Anza Land Co. in Borrego Valley for several years. Their yields were maximum without application of any pesticides for over five years. Unique to this production system was the alternative harvesting pattern of alfalfa hay plantings surrounding the cotton."

Harvesting alfalfa before it matures keeps the plants in a stage of perpetual youth, the stage favored by phytophagous (plant-eating) insects. However, when the whole alfalfa field is mowed at one time, the phytophagous insects either move to other crops or their numbers drop until the alfalfa grows back. Mowing the alfalfa in alternating strips ("strip cutting") maintains a continuous food supply for phytophagous insects that, in turn, host a huge number of beneficial insects. The alfalfa at the De Anza Land Co. acted as a gigantic nursery for beneficial insects, especially the tiny Trichogramma wasps that parasitize cotton worms. Strip cutting also prevented lygus bugs from being forced out of the alfalfa and into the cotton. According to Dietrick, 'There are 1000 or more species of insects in unsprayed alfalfa. The beneficials living in alfalfa leak out into surrounding crops to control all kinds of other pests. Today we've lost the alfalfa nursery because of pesticide spraying, so we have make our own beneficial nursery by planting cover crops. If we could only keep alfalfa off of spray, we'd solve a lot of pest problems."

Mass Sampling of Insects

It was also during these years that Dietrick and Evert Schlinger invented the D-Vac, a vacuum that pulls air through a nylon mesh screen to collect insects in the field. With a D-Vac, a field scout can standardize samples from field to field, getting a much more accurate picture of the relevant ecosystem. "Experience using the D-Vac vacuum insect sampler reveals information that allows for predictions of the progress of biological control," says Dietrick. "Much conventional sampling reveals damage as hindsight rather than as insight for predicting what is about to happen. This lack of reliable, current information generates fear, which triggers preventive spray programs. If in doubt, treat! Such treatments are often applied too late and destroy more beneficials than live pests." In Dietrick's experience, by the time sprays are applied, beneficial populations are surging, and most of the pest damage that triggered the spraying has already occurred. "The cost of the destruction of the natural enemies must be added to the cost of the pesticide application and to the longer-term loss: the dead beneficials cannot be economically replaced in time for the next pest crises."

Pictured here is the Trac Vac Insect Collector. This is a large version of the D-Vac., which was a hand-held collector. The Trac Vac was used for non-chemical control of aphids and alfalfa weevils, Hypera brunneipennis. As the tractor was driven down the alfalfa borders the insects in the canopy of alfalfa, both pests and their natural enemies, were collected alive in organdy bags. When the bags were emptied, the beneficials were allowed to fly back into the field and the aphids and weevils were destroyed.

In their work with parasitoids of the alfalfa weevil, Dietrick and van den Bosch used the D-Vac to collect large numbers of parasitoids. "We would go to the area near Escondido where the parasites were established, vacuum a whole field, put the insects into sleeve cages and aspirate out the parasites we wanted. Then we'd release them in other areas. The alfalfa fields were our most economical insectaries. We probably couldn't do that today because of the restrictions on the movement of insects."

The spotted alfalfa aphid, Therioaphis trifolii, invaded New Mexico, Arizona and California about 1954 and within two to three years it had spread to over 30 states. As many as 14 treatments with organophosphate insecticides were used on a single field in one year. Three parasitoids imported from Europe and the Middle East ultimately played an important role in controlling the aphid. "We spent one year harvesting parasites [with the D-Vac] from our test plots and distributing them to farmers. We collected mostly parasitized aphids to give to them because that was the best way to introduce the parasites to a new field. All parasite stages except the adult were represented in the parasitized aphids, and they were naturally grown and vigorous. Sometimes bugs grown in the lab have a hard time making it in the field. In fact, we were having trouble rearing parasites in the lab because it was very difficult to get alfalfa to grow in pots. Farmers would come from all over and we would send them home with some fresh hay and a handful of parasitized spotted alfalfa aphids in a paper bag. We told them to dump the paper bag in a corner of the field and not to spray there. In one year, the cost of pesticide used for that aphid went down from $9 million to only $500,000."

Trichogramma Enters the Picture

Meanwhile Stubby Green continued Rincon Insectary and learned how to raise Trichogramma on Sitotroga moths from Dr. Stanley Flanders. "Dr. Flanders had organized the first mass production facility for growing Trichogramma on Sitotroga moth eggs in 1929 for the Saticoy Walnut Association. Stan researched Trichogramma throughout his more than fifty-year professional career and was a world authority on biological control. His expertise about Trichogramma was sought from countries all over the world."

In the late '50s, the Green brothers were approached by a Mr. Stoltenburg, a cotton farmer from Texas, who wanted them to mass rear a species of Trichogramma for the cotton bollworm. Stoltenburg was raising them himself but wanted to produce more parasitoids in order to expand his market. He and the Green brothers, along with Jack Gothard, a Texas cotton gin manager, began marketing Trichogramma throughout the southwestern U.S. "The product was referred to as "Trichos" and the market was substantial. There was sufficient money to hire another entomologist just to help develop sales in the field."

Dietrick was offered the job, and because he could see the potential commercial market for his skills, he accepted the offer and resigned from U.C. "Insects were grown without firm contracts or promises to purchase. They were mass-produced at Rincon Insectary in California and delivered to Gothard in Texas, who sold and released them on demand."

"I spent the 1960 cotton season in Texas, ending up in Nicaragua sampling cotton insects with the D-Vac vacuum insect net. That summer I sold my first Trichogramma to a California cotton grower named Neal Jack. I formed a company to manufacture the D-Vac and later that fall I made my first sale of a Model 1 backpack D-Vac and a Trichogramma release program to Mr. Hagie, a large cotton grower in Nicaragua. This was the first of over 1500 D-Vacs that have been distributed throughout the world to date, and this was the start of over 30 years of selling Trichogramma to Central American cotton farmers."

Changes at Rincon

In the summer of 1960, Stubby Green was diagnosed with lung cancer and died a year later. "Needless to say, this was a shock to the business. I obtained stock ownership and became president of Rincon Insectaries, Inc. Stubby's wife Amelia, his brother, Douglas Green and Stubby's stepson, Jack Blehm, were the other stockholders of record. Rincon lost the connection with Gothard in Texas when Gothard failed to pay for his insects and instead built his own insectary."

After these setbacks, Dietrick and Jack Blehm struggled to develop California markets for the Aphytis and Trichogramma they were producing. By this time more people were becoming interested in "supervised biological control."

"Fillmore Citrus Pest Control District contracted for Aphytis in 1961, and entomologists John Nickelsen of Shafter and Louis Ruud of Kerman helped us sell Trichos for cotton in the southern Central Valley. The income came mostly from acreage charges for implementing programs of supervised control using insectary-reared and field-harvested parasites and habitat management advice in cotton."

Dietrick and his daughters Jan and Karen are shown separating collections obtained with the D-Vac

In 1962 Blehm and Dietrick formed a Mexican corporation called Rincon de Mexico to grow Trichogramma for cotton farmers in Los Mochis, Sinaloa, Mexico. With the help of many people, Rincon expanded their market into the Imperial Valley of California and into Arizona, New Mexico and West Texas, competing there with Gothard's insectary.

Rincon Prospers

The primary boost to sales came when they began working with John Elmore, Sr. on his Salton Sea, CA "Desert Ranch." This was an influential ranch, an experimental cotton farm for growing seeds of cotton varieties developed by the Deltapine Company, and many of the farmers in the valley followed the changes on the Elmore ranch very closely to see whether or not they would work. John Elmore had 5000 acres in alfalfa and cotton and was spraying his 2000 acres of cotton every week. The first year Rincon took over the pest management of his cotton, a bad infestation of cutworms forced them to spray with Endrin to get the cotton to come up; however, the rest of the season they kept the pesticide bill under $30 per acre even though they had problems with the cotton leafperforator. Elmore began strip cutting the unsprayed 3000 acres of alfalfa that year, and Rincon released insectary-reared Trichogramma as well as field-collected beneficials. Dietrick harvested beneficials by using a gargantuan D-Vac with a 20-foot sweep that was the equivalent of 12 regular D-Vacs. "We built a room-size plastic tent and we'd dump about two feet of insects on the floor and then go in and aspirate out the ones we wanted. Not many people have experienced something like this. We got to see rare species that ordinary sampling would have missed, and it gave us so much insight into the way biological control works."

The following year John Elmore's ranch went unsprayed. "Of course this was before the invasion of the pink bollworm when the lack of sufficiently effective parasites drove farmers back to broad-spectrum pesticides. When you have to spray for one pest, generally the farmer must spray for all pests; thus returning to short term total chemical management programs even though he knows resistance will develop. Pinky is still the impediment to growing cotton throughout the world, especially in the Imperial Valley."

To increase insectary space for Trichogramma production for their cotton market, Dietrick and Blehm bought a half interest in Vitova Co., an insectary near Riverside started by Dr. Stanley Flanders and his son Phillip to produce Sitotroga moths and eggs for aquarium fish food. 'The insectary was located in a house, two railroad box cars and three large abandoned mushroom production caves. The name Vitova is a contraction of 'vita ova', Latin words for live eggs.

Rincon-Vitova

On January 15, 1963, Vitova was incorporated, and a few years later the stocks of the Rincon and Vitova corporations were merged into the insectary we know today as Rincon-Vitova.

Rincon-Vitova hired Max Badgeley and Charles Musgrove, two U.C. Department of Biological Control technicians, to help mass produce and market green lacewing eggs and filth fly parasitoids. This change increased their product diversity, enabling them to sell to a wider variety of fanning enterprises and to extend their marketing season.

Using Fred Legner's research with biological control of filth flies on poultry egg farms, Rincon-Vitova added a program of supervised biological control for filth flies. Vern Stern studied trap crops and natural enemy enhancement in cotton using interplanted strips of alfalfa and resident weeds, and Dan Gonzales contributed Trichogramma research. "Nearly all of our programs were developed from ideas generated by researchers. Often they were common sense ideas that were left unfunded in university research for lack of any commercial advocacy by farmers. It seemed that much of the time there were political forces that stopped funding for unknown reasons.

More Restrictions

Dietrick says that today there are still political problems surrounding biological control research. Although the funding for biological control has increased, biological control is now considered by many to include the use of genetically engineered plants and insects, and money is being diverted from classical biological control to the perhaps flashier science of biotechnology.

Today, the greater number of restrictions on the movement of insects hampers biological control research and commerce in needless ways. Says Dietrick, "Restrictions have increased, perhaps because people do not understand or believe in the balancing of complex systems that underlies the success of classical biological control projects. Education seems to have skipped a generation, and we have to prove very useful theories all over again at greater and greater cost to both agriculture and the environment."

"It has been harder lately to get permits from the USDA and sometimes even from the local states to import or ship well-proven beneficial insects. Or you get the latest instructions and then a few months later they tell you the rules have changed, or you filled out a form wrong. Sometimes shipments are held up and the insects die, even though we have permits. Then we have the Department of the Interior Fish and Wildlife Service, which has another set of laws and fees for our industry. Our products play such an important role in the conservation of endangered species that you would think Fish and Wildlife would put support of our industry as a top priority and even give us subsidies or tax credits, but instead we get repeated threats of enforcement of more and more laws with so-called 'teeth'. It is unfortunate that as all the different regulatory agencies go after their current agendas, it adds up to senseless obstacles to the biological control industry." [Ed Note: Some industry leaders believe the problem stems from a lack of clear policy. There are many regulations and enforcement is uneven.]

The Importance of Rincon

A continuous stream of young entomology students from UC Riverside has found part-time or seasonal work at Rincon-Vitova. "A lot of dedicated and talented people worked for us and then went on to do big things." As California began licensing pest control advisors (PCAs) and more small businesses sprang up, the income from the insectary side of Rincon-Vitova began to dominate the field monitoring services. "Competition from insectaries started by former employees drove us to focus on new markets including some overseas clients."

Today Rincon-Vitova raises 12 species of beneficials, markets a great many more and still provides some field monitoring services. "My field monitoring services are limited now because I don't drive as much," says Dietrick, but he gives pest management and insect rearing advice on the phone to hundreds of people.

Dietrick is dedicated to encouraging the use of biological control and has always welcomed visitors to Rincon-Vitova, many from far-flung parts of the globe. "We have always maintained an open house to most interested visitors, including researchers and potential competitors, because we found that we learned more from many of these brief encounters than we gave away. Thousands of visitors have viewed and taken pictures of our facilities and continue to do so, while most other commercial insectaries are off-limits. Some have gone and built better ones. I've always felt that the only way to expand the use of biological control is to be open and share information, communicate! I had some fear that I might run out of customers, but the continued marketing of broad-spectrum pesticides creates so many problems that I'll never run out of work or customers." Certainly Rincon-Vitova's open-house policy has fostered the tremendous growth in commercial insectaries in the last 20 years, and many a small insectary throughout the world is indebted to Dietrick's generosity and commitment to biological control.

Pesticide Education

"My goal, says Dietrick, is to teach farmers how to farm so that they won't need to buy the insects I sell. There are so many pests that we have created ourselves, pests like the lygus bug, the cabbage lopper and the beet armyworm. They weren't pests before we started spraying hard pesticides in California and they would go away if we stopped spraying now. We still have a 'pesticide mind-set' in this country. According to Lester Brown in his book, Vital Signs in 1994: Trends that are Shaping our Future [by Lester R. Brown, Hal Kane and David Main Roodman, published by the Worldwatch Institute], 520 insects and mites are resistant to one or more pesticides and 17 insects are resistant to all classes of insecticides. Fortunately, lacewings in southern California have also become resistant to pesticides. They're the only predators left down there and without them the farmers couldn't grow anything. The way we farm creates a problem, and it's hopeless to talk to anyone but the farmer."

The Future of Biological Control

Dietrick says there's not as much classical biological control going on now. 'These skills are becoming lost for lack of funding at a time when there is more need than ever. New exotic pests are more prevalent each day. Budget restrictions leave [these exotic pest projects] underfunded for classical biological control research. The commercial for-profit insectary has been excluded from meeting this challenge, and, at the same time, farmers perpetually endorse hundreds of millions of largely wasted tax dollars for eradication projects."

Researching the complexity of agro-ecosystems is imperative for future implementation of biocontrol, says Dietrick. "You can't judge the success or failure of biological control by looking only at percent parasitism. The system and the interactions between the pests and all the various natural enemies are so complex. We need to look at the whole ecosystem around the pest to find out what is really going on."

And his advice to young people interested in pest management? "You've got to learn the insects and you have to have practical experience. Get some kind of internship. You just can't get enough training from school. I tell young people to get a job with a chemical company, get to know all their customers, then quit and do IPM for those customers."

Riverside man raises beneficial insects

Alternative to massive pesticide use

By TOM PATTERSON

The Press, Riverside, CA, 7-31-1973

Producing beneficial insects to fight insect pests is a rapidly growing business for Everett Dietrick, former biological control scientist at the University of California, Riverside.

His firm is expanding; an indication that total reliance on the massive use of insecticides is waning.

Dietrick's company, Rincon-Vitova Insectaries Inc., with 21 employees, operates on El Rivino Drive in the Rubidoux area and at Oak View in Ventura County. It is starting a new and potentially larger operation in a former defense laboratory near Milpitas, to serve central California agriculture.

This, he explained, "is a very small drop in the bucket compared to the multi-million-dollar pesticide business." He is competing with that business, not with the idea that no one should ever spray insecticides on bugs. He does believe that the all-out spray chemical programs are falling as long-term solutions and that there will be more emphasis on his approach.

He identifies himself with integrated control - using sprays only when only where a clear and present danger exists.

Dietrick sells two products -insects and advice. He and his associates contract to provide pest management by the acre to farmers. Some independent entomologists are also selling integrated control advice, he said, most of them use Rincon-Vitova as a source of beneficial insects.

He modestly increasing success, Dietrick said, "is due to economics, not to moral preachments about ecology. The all-out use of insecticides reaches a point where the cost keeps rising and production goes down.

"But it's awfully hard to get away from a program that has been successful. Even though the new insecticides cost a lot of money, they worked; or, if one didn't work, another was found that would."

Dietrick's company improvises. He utilizes outmoded refrigerator freight cars to insulate his insect rearing, to hold down air-conditioning costs.

On rows of banana squash on shelves, scale pest insects are growing in heavy incrustations, and this presence of pest insects says something about biological control.

"IN ORDER TO produce good insects, you must have bad ones," he explained.

The good ones feed on the bad ones, often on a specific bad one, leaving other insects alone.

In the railroad car where housefly enemies are produced there's a noxious odor of rotting stuff - for the flies to eat

The Rincon-Vitova inventory includes the pale green lacewing for use against aphids, mites, moths and caterpillars.

Ladybugs are collected in the field. In the insectary, they are preconditioned so they're ready to feed and lay eggs when they encounter aphids.

Trichogramma wasps, tiny and harmless to people, are parasites on moth and butterfly eggs. They are used to combat the worm pests of cotton and numerous other economic and ornamental plants.

Everett Deitrick tends his banana squash, hosts to scale insects, which in turn are used as hosts for eggs of the parasitic golden chalcid, a beneficial that attacks red scale in citrus orchards.

SOME BENEFICIAL insects, like lacewings, are sold in larval form. Trichogramma, golden chalcids and some others are sold as adults, ready for release. Fly parasites are delivered while they're maturing in fly pupae, to be placed where they'll emerge to protect poultry or cattle.

The latest Rincon-Vitova product list has 35 different Insect species.

The last work Dietrick did as a UCR technician was in connection with the outbreak of the spotted alfalfa aphid in the 1950s. Typically, it had arrived from the Middle East where it is scarce and evidently held under some type of natural biological control. In Riverside County, it multiplied as an insect can under the right circumstances - with a plentiful food supply (alfalfa) and without natural enemies.

Several parasite wasps were found In the Middle East to combat the aphid.

"In that work," Dietrick said, "we field-harvested the parasites and moved them to other fields. It took two years to reach a natural balance that might have taken 10 years to accomplish by leaving the parasites to spread natural, DIETRICK SAID many factors contribute to the growers' dilemma with insecticides. Initially, he said, the new insecticides clean fields and groves of harmful insects. The early result is usually big crops with few rejects.

Sometimes, as in Imperial and Palo Verde Valley cotton, the spray program is area-wide - most growers under a uniform contract to spray at regular intervals, whether they need it or not.

Such a program, Dietrick said, eliminates beneficial insects. Eventually, the damaging pests become resistant through the survival and reproduction of the few that are naturally resistant.

By contrast, the integrated control program calls for releasing beneficial insects only after the first damaging ones appear so beneficial ones will have food to encourage them to stay.

ANOTHER PRACTICE goes hand-in-glove with the goal of completely eradicating insects, Dietrick Said - the practice of keeping fields and orchards clean of weeds.

"It saves water," Dietrick explained, "but it also destroys a refuge for beneficial insects. You don't have to leave all the weeds; a row or two in an orchard may suffice."

Or, If cotton mass production is involved, a strip of alfalfa here and there permits beneficial insects to winter.

The pink bollworm pest of cotton, however, poses a problem for biological and integrated control, even as it does for the cotton grower.

It's a godsend, at least temporarily, for the chemical spray industry. No really effective biological control agent is known.

Because he can't control the bollworm but only hold it back a little, Dietrick advises his Coachella Valley clients to spray but not as much as do most cotton growers in the Imperial and Palo Verde valleys.

There, under valley-wide group contracts, growers have had as many as 15 sprays in one season. Most Dietrick clients sprayed only four times, tolerating a higher incidence of bollworm and saving control costs.

But conditions differ. Coachella Valley produces comparatively little cotton, scattered among other crops. Imperial and Coachella Valley cotton grows on larger areas, removed from other crops. This year, foreign purchases have raised the cotton price. Growers are seeking maximum production, leaving biological control for the future.

Dietrick, as well as growers who pay spray bills are hoping that another line of attack on the bollworm may succeed. UCR experimenters have been using a chemical called hexalure, which approximates the chemical used by the female of the pink bollworm to attract a mate.

This opens the way to confusing and misleading the male. It may result in control by natural chemicals, rather than by all-purpose pesticides.

Such control would be compatible with Dietrick's approach to other insect pests, without the harmful side effects of all-purpose sprays.

Although he's primarily in the business of raising insects in insectaries, Dietrick says the integrated control outlook contemplates that most beneficial insects of the future will be raised in the fields.

This insect expert flies in the face of convention

Joshua Siskin'.s column Gardening, in Daily News(Los Angeles), Saturday, November 18, 1995, p 15

There are few people like Everett "Deke" Dietrick. If there were more like him, insect pests would cease to be a problem on Earth.

It would be a gross understatement to categorize Dietrick's understanding of insects as profound. Dietrick knows insects the way an author knows characters in his books or a mom knows her kids.

Dietrick's specialty is biological insect control, the pest-management strategy that utilizes predaceous and parasitic insects to keep populations of insect pests at bay. Forty-five years ago, Dietrick started the world's first commercial insectary, or insect farm, in his garage. Insectaries grow large quantities of beneficial insects that feed on insect pests.

Dietrick raises lacewings and parasitic wasps in Ventura and sells them to commercial and backyard farmers. The process involves several stages. To mass-rear beneficial Trichogramma wasps, which are used on such pests as the European cabbage worm, Sitotroga moths first must be raised. With their hind-end ovipositors, the wasps - which are smaller than pinheads - pierce the moth eggs and deposit their own eggs within. The larvae that hatch out of the wasp eggs eat out the insides of the moth eggs, after which the wasp larvae pupate and emerge as adult wasps that will continue to oviposit in more moth eggs.

Lacewings - half-inch long creatures with light green Wodies and diaphanous wings - are the indestructible workhorses of insect biological control. They have proved resistant to every pesticide and are effective at controlling most caterpillar pests. Most beneficial insects, including ladybugs, are killed when pesticides are applied. When a ladybug chews on a pesticide-laden aphid, the pesticide passes into the ladybug's body. However, since lacewings suck the juices out of insects, rather than chewing on their exterior shells, which are more highly concentrated in applied pesticides, they are better able to survive pesticides.

You don't have to purchase beneficial insects to bring them into your garden. Lacewings lay their eggs on bottle trees (Brachychiton populneus) and California lilac (Ceanothus spp.). Parasitic wasps visit gardens where yarrow and common fennel are found. Among the best plants to grow for attracting beneficial insects are grasses. whether Sudan grass, ornamental grasses or cereal grasses such as corn.

It is always a pleasure to talk to someone who speaks the truth and debunks popular myths; Deke Dictrick is such a person. Conventional horticultural wisdom holds that tomatoes and corn should not be planted together, since the caterpillars that feast on corn also will eat up a tomato crop. Yet Dietrick has found that if corn is planted around tomatoes, beneficial insects - such as lacewings

- will be attracted to the corn and curtail caterpillar development.

Dietrick also took exception to the current method for dealing with the Mediterranean fruit fly. Millions of irradiated, sterile fruit flies

- shipped in from fly farms in Guatemala - are released in Los Angeles County each week; any fertile flies that are living in this area will not produce offspring after mating with a sterile fly. Dietrick maintains that to more effectively combat this pest, natural insect predators of the Medfly should be imported from the Cameroons region of Africa, which is the Medfly's original home.

When Dietrick first got involved in biological insect control, pesticides were not yet widely used in agriculture, and the government was a big sponsor of biological control projects, especially in California. After World War II, with the advent of powerful pesticides such as DDT, it was thought that all insect pests soon would be eradicated, and there was no need to continue with biological methods. Chemists displaced entomologists as the leading authorities on insect control.

It soon was discovered, though, that no pesticide could completely eliminate an insect pest. Resistant

populations developed that created the need for other pesticides, a spiral that has continued to the present day. In recent years. as pesticide application costs have skyrocketed, farmers have begun to return to biological control.

Joshua Siskin'.s column appears every Saturday. He welcomes questions from readers. Write to him in care of the Daily News Features Department, P.O. Box 4200, Woodland Hills, CA 91365-4200. Topics of general interest will be discussed in the collumn