Short History of IPM/BC Work by William and Helga Olkowski, and Associates -- 1968 to about 1998

By William and Helga Olkowski

Our pest control work over 30 years was stimulated by knowledge of the side effects of pesticide use. Our bias when I started work as a graduate student was less is better, best was zero. A chance meeting with Dr. Robert van den Bosch, then head of the Division of Biological Control at UC, Berkeley, changed my life. I (WO) reentered graduate school working on a classical importation project. Although I was officially the student, Helga was the key but unacknowledged “helper” in these early days. “Van” as we all called him was known worldwide as a biological control foreign explorer and anti-pesticide campaigner (see his book The Pesticide Conspiracy”). He would occasionally show us his hate mail as an example of what he was up against. These letters were frequently from Cooperative extension agents who were public employees (USDA) at different colleges and agencies around the US. Surprisingly some letters threatened death. These were hard to understand until we experienced the same sort of threat when trying to speak about our work in one Southern city.

Van was disgusted with the entomological professionals who failed to understand how much pesticide use was unnecessary. His work with cotton on thousands of acres comparing different pesticide treatments presented at the National Entomological Society meetings was met with disbelief. His work showed that the untreated check plots were producing more cotton than any treated plot. This was regarded as a poor experiment. This left him with an awareness that science alone was not the answer but social/political change was needed. We collaborated with van because he was a courageous person and we agreed with an overall objective of reduced pesticide use. We thought it was also a critical public health objective. Of course we were tarred with the same brush as van and consequently had to run the same smear gauntlet he ran as an anti-pesticide environmentalist, but without the protection provided by a full professor salary and tenure. Some of the same smears fell on us originated from the University of California at Berkeley, which was surprising when traced. Although I now regard those academic systems as pools of jealousies, petty quarrels, and backbiting, there were many good people there who helped us. Our work in pest control is summarized below divided into 4 sections: 1) Urban Biological Control, 2) Integrated Pest Management (IPM), 3) Institutional Development, and 4) Professional and Public Education. We realized early in our careers that urban areas, with predominantly aesthetic vegetation, were virtually unexplored with an IPM or BC focus. Most research in pest control was devoted to agricultural pests and then any pesticide applications for horticultural purposes were based on the same or similar research without consideration of the urban context. In urban areas pesticides are used in close proximity to potentially many more people than when the same pesticides ware used in agriculture. If an insecticide was judged “safe” by the pertinent Federal agency for agriculture, it then was safe for urban applications. This was a gross simplification at best, at worse an example of how poor the regulatory process was. When a city uses a mist blower to treat a 50 ft tree there is no way to confine the poison to the tree. It’s like pumping an aerosol poison into the air of the city so the margin of safety should be set much higher than in an agricultural setting.


The importation of the original natural enemies of a pest invader is the most powerful pest control method because it is non-toxic and permanent. Our first project – started as a graduate student, was planned and organized by van, who in his normal travels around the world for natural enemies of agricultural pests (examples: alfalfa, cotton and walnuts) knew of a location in Rome where the key natural enemy of the Linden Aphid could be collected (i.e., Trioxys curvicaudus: family Ahidiidae). The linden aphid’s honey dew was excessive on about 100 large linden trees in the city (See Bioscience article, and California Agriculture). Honeydew, excreted by the aphids was a nuisance producing sticky feet and damaging finishes on vehicles. All were large trees, some over 50 feet. He collected this species in Rome and sent then back to the importation laboratory at the University of California in Albany where the natural enemies of the natural enemies (called hyperparasites) were removed. They were then released to me.

Our job was to release this species in protected locations where they would not be killed by pesticide applications. This aspect of the work turned out to be the critical component of the job as the following section describes. The importation of this natural enemy turned out to be a stunning success. Since this whole effort was a vast personal learning frontier for me I was using the project to discover the hows and whys of biological control work (see IPMP what’s really involved) and its key components.

The problem with sampling large trees was somewhat ameliorated by the use of the city of Berkeley’s 55 ft lift truck which allowed me to sample at many different parts of the trees. With pests that had been sprayed for decades now entirely controlled by just hydraulic water washing most of the leaves that first season (1971?) were lost due to high aphid populations. But the trees refoliated and did not die. I found a lower canopy part of one of the tallest lindens on Albina St. near my home at that time for releases and later sampling to see if the parasitoid established.

During that first season no parasitic insects were detected. An early sample the next spring showed new mummies indicating establishment. The released species was recovered after emerging from the mummies. Thereafter the aphid, though present, was not common, certainly never at the levels seen when pesticide applications ceased. The troublesome honeydew disappeared.

The awareness of what this “discovery” meant to us over the years grew. Looking back now after decades I can say that the first hand experience with such a successful importation convinced me that importation of the right natural enemy was the most powerful pest control method. We reasoned that it should be the first line of defense against any introduced pest. Of course this could be acknowledged by many entomologists today, but then biological control was almost a secret, practiced by very few researchers. Still, it remains a minor part of the methods available today for pest control requiring public support, because when a pest population is driven below injury levels by natural enemies no one can make a profit by reselling it. Most if not all politicians remain ignorance of this fact. And to get public support one needs political support.

Further, when one explored for ways to report such results the possibilities for publication were limited. These importations are not experiments in the classical mode so do not fit the standard scientific paper format. Just what is the experiment? Is it a unique attempt, or a series of attempts to establish or, more precisely, reestablish a natural enemy and thus restore an ecosystem? One could compare before and after importation populations but this is very difficult. In addition, publishing at that time meant the author(s) had to pay page charges, about $90/page, assuming the editor accepted the paper for publication, itself a difficult task.

So, a short article meant hundreds of dollars, which we did not have. These realizations later led to our development of the two journals we used for many years to hold our “discoveries”: the IPM Practitioner and the Common Sense Pest Control Quarterly, both distributed around the world through a non-profit called the Bio-Integral Resource Center (BIRC), discussed further below.

One other observation based on this project is relevant to our career development. After seeing how effective this parasitoid was in controlling the pest we discovered that it distributed itself throughout Berkeley. Apparently, parasitized winged adults could distribute the parasitoid without further colonization attempts on our part. But we also wanted to speed up distribution it to other communities.

We had the opportunity to move the parasitoid to Sacramento, where linden trees formed the major plantings leading up to the capital. We released mummies from our laboratory colony one year in shrubs nearby trees that were routinely sprayed. We did this without contacting the city park department. The next season we returned but the trees were clean of aphids (from spraying) and no parasitoids could be detected. I concluded that our control of the whole spraying process was needed if the biological control agents had the any chance of establishment. This shifted our emphasis to development of IPM programs as our primary focus. This is discussed further below.

Urban Integrated Pest Management

Work with the city of Berkeley continued after the successful establishment of linden aphid parasitoid, later the elm aphid parasitoid, Aphidius tenuicaudus, (from Iran) and the tulip tree aphid, Aphidius liriondendri (see city reports). Riding high we thought we could continue going down the list of aphids of the local cities but this would require a rather long term commitment which we could not support without public funding. So then it was clear that a means of funding was needed but to get that support required a big public education effort.

Subsequently we built a service system around a logical framework of monitoring, establishing injury levels and evaluation of treatments. We borrowed and expanded upon the IPM framework then developed in Ag and adapted it for the urban environment. The treatments selected were based on a toxicity gradient, first the non-toxic methods, next least toxic methods, and subsequently gradually increasing where methods were not successful, to more toxic means. We were fortunate in realizing that water and soap solutions were enough in many situations to manage citizen complaints. We did some evaluations of using soaps at first and later Safer came up with their commercial Safer Soap Insecticide. We never go around to evaluating various ammonia or alcohol solutions reported by some to be effective. To be safe one should wash soap solutions from leaves as they can damage some plants. The Safer product was the safest from this standpoint and it was a registered product with full Federal clearance.

Further, we also realized that when actually tracking the decision-making process for treatment, the criteria for treatment were weak at best and in many situations lead to unnecessary treatments. Also, we were an early adopter of work with the highly selective microbial agent Bacillus thuringiensis (Bt) (under the guidance of Dr. Dudley Pinnock then of the insect pathology division at UC, Berkeley). Thus we had the nucleus of a set of not toxic controls for most insect pests on the shade trees of the San Francisco Bay Area.

After developing this set of controls a bit further we started work with the city of San Jose (almost 200,000 trees), Palo Alto, Modesto, San Raphael, and Davis (about 500,000 trees in total. These developments are covered in the reports for the different cities (see City reports) and the summary included in a report to the State of California’s Dept. of Food and Ag (see table X from that report (State Reports – D.F&A, Year?). See also EPA 6- year summary report on natural enemies of shade trees, including an unsuccessful attempt to introduce the parasitoid for the silver maple aphid. See xx for a summary of the shade tree aphids we worked on.

Using a systems approach we applied the same framework we used with shade trees to the Palo Alto School District, and other school districts (Flint MI, and Washington D.C.). These efforts resulted in various educational tools created by staff people who had considerable autonomy. We also adapted this same concept to the California Department of Water Resources, where “weed” and ground squirrels were the primary problems.

Later we branched out to the National Park System, first in Washington parks (working with the National Capitol Region) and through that initial effort to affect the whole National Park System. After 3 years on contract with NPS we were told that about a 70% reduction in overall pesticide reduction was documented. This was aided by adoption of IPM as federal policy, and the result of a course we designed and taught to an initial group of resource managers. The course later was used to train all 300 or so park managers from around the US and has continued for years since.

As most of the publications describing these problems and how we went about this work were described mostly in government documents few people were exposed to the actual observations and field data, which formed our core learning. None of this information would find its way into articles, book chapters, etc. and other outputs so we are making them available through this website. A great many of these examples could use further work by graduate students and researchers looking for projects. We were not in a position to do deeper research on the pertinent biology in most cases. This was because we could never get the necessary funding. An example will suffice.

At one time we spent a great deal of time with the encouragement of a project officer at the National Science Foundation to innovate by implementing a city-wide pilot PIPM program covering all a city’s pest problems, including rats and mice, horticultural pests in parks and street-side, schools, etc. After a great deal of work we submitted the proposal and waited. Then after a few weeks we received this message: “you are too out there in the real world.” We concluded that scientific work was rather restricted to the usual practices and could not encompass a real pioneering effort. This further strengthened our belief that going directly to the public was the way to proceed. This lead to the development of our primary institutional vehicle, BIRC and its two international journals (the IPM Practitioner and the Common Sense Pest Control Quarterly) as well as a major effort in producing a series of publications aimed at the general public (see Educational Materials).

Institutional Development

There are only four paths for career development from which a newly minted PHD could search for a career path: as an academic, as a businessman, as a scientist or employee within a government agency, and the non-profit sector. I tried to obtain a job for an academic position thinking we had years of experience with aphid biological control. I was turned down when I applied for an urban entomology position at UC, Berkeley, but through that process learned that professors like to have their own students get these jobs and therefore find ways to be on the selection committees.

In retrospect, it was a good thing that I did not get this job because I/we went on to gain practical experiences that lead to a more solid development of the IPM paradigm. This includes example IPM programs for weeds, vertebrates and plant pathogens besides continuing to expand on insect IPM. None or few of which would have been possible working within the confines of an entomology department. But the salary and technical help would have been great.

There is also the applications of systems concepts that could not be explored fully if confined to an entomological view only. For example, our work with composting: we saw backyard composting as a way to minimize fly production, compared to what an average garbage can produced. We made such an announcement on the TV one evening and were called on the carpet for deviating from the narrow concept of entomology.

Composting was a mycological method. But the academics viewed it narrowly and could not stretch their minds to composting as a means of pest control. This also became one of our foci for public education. The public could easily think systemically while the academics could only focus taxonomically. These and other experiences lead us to focus on developing our own non-profit. This also turned out as a way in which a husband and wife team could function. Academia looked askance at husband and wife collaborations.


Fieldwork in a city environment inevitably leads to interactions with local citizens wanting to know what we were doing climbing ladders, etc., (see photo from CAL Ag). After any number of times explaining what we were doing, we decided to save time and make an information sheet to carry the message to citizens. These gradually expanded in dept and scope as we identified areas of interest. It was a pleasure to meet many of these people who expressed genuine interest and frequently delight to learn about natural enemies and the biology of different pest insects. The idea of natural enemies seemed poorly developed in the public eye. Since our funds were from public sources we felt an obligation to educate the public. At the University we regularly ran into professors who distained public educational efforts. The aggravation caused by busloads of the public visiting our lab was surely responsible for some of the animosity our project generated. This was part of the reason we left the University and moved into the non-profit world. Gradually, we came to realize that most of what we were publishing was for professional people involved in pest control so we needed a vehicle for educating the public so they could demand IPM services from these professionals. One of our journals, the Common Sense Pest Control Quarterly was designed primarily for the general reading public.