Historical Press Coverage
Dietrick - Biological Control Pioneer, The IPM Practitioner, V 17, No 1, Jan 1995
man raises beneficial insects The Press, Riverside, CA, July 31-1973
insect expert flies in the face of convention Daily
News(Los Angeles), Nov 18, 1995, p 15
Everett Dietrick - Biological
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
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"
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
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
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
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
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
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
"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.
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
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
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.
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 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.
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
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.
"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
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
||Dietrick is shown with his grandson Jack in 1992.
Riverside man raises beneficial
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,
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
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
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
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
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
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
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.
"That's what we did to control the spotted alfalfa aphid," he explained.
"I look forward to a time when I can get most of the insects I need from one field
and release them in another nearby. They have a better chance of doing the job when
they're raised in the field and they cost less."
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
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
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
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