My primary pursuits at the University of Illinois are to conduct applied entomological research and disseminate the scientific findings to clientele. The primary objective of my research efforts has been to improve the management of field crop insects, thus enhancing the economic interests of producers. Broader benefits have ensued, most notably alleviating the adverse effects of agricultural production on the environment. Following are examples of research projects under my direction that illustrate this approach.

Since western corn rootworms were found in Illinois (1964), there have been many questions and uncertainties regarding the use of soil insecticides for corn rootworm control. More money is spent annually for control of corn rootworms than for any other insect pest in the United States. Most recent estimates indicate that approximately 3 million acres of corn are treated annually in Illinois at an annual cost of $45 million. The addition to the economic impact of soil insecticides, the use of these products heightens concerns about environmental contamination and threats to human health and safety. For many years, producers throughout northern Illinois have inquired whether they could reduce the rates of their soil insecticide applications. Historically, the heaviest concentration of corn rootworm problems occurred in northern Illinois due to the lack of crop rotation. In 1990, I began to coordinate a participatory on-farm research project with 29 producers from 10 counties. The fundamental question was whether producers could reduce their insecticide rates by 25% and still maintain satisfactory levels of corn rootworm control. In addition, many of the producers were interested in learning how to monitor corn rootworm beetles with traps in their cornfields. Plots on each farm were evaluated for corn rootworm injury, and yields were measured. Results from these experiments revealed that producers could reduce their soil insecticide rates and not sacrifice root protection or yield. The economic benefits of this reduction in the amount of insecticide used in Illinois are estimated conservatively at $11 million annually. Cooperating producers also were able to validate the usefulness of traps as a pest management tool in their cornfields. In addition to the economic benefits, the results of these participatory on-farm research projects translated into environmental benefits due to reduction of the application of soil insecticides at unnecessary rates.

During the series of on-farm projects, producers became very interested in different corn hybrids' ability to compensate for corn rootworm injury. Some corn hybrids tolerated or compensated for corn rootworm larval injury, others did not. Information about corn hybrids' tolerance to corn rootworms was not well established. Beginning in 1993, I coordinated experiments in central and northern Illinois designed to evaluate the ability of the most commonly grown hybrids to compensate for corn rootworm larval injury. Because of the potential for weather conditions during the different growing seasons to affect the root growth of hybrids differently, the investigation was continued for four years (1993-1996). Because of this long-term research effort, producers asked agronomists with seed companies for hybrids that had similar genetic backgrounds as the corn hybrids in our study. In essence, producers were able to select hybrids that are able to tolerate corn rootworm injury better. Scientists who are developing transgenic corn hybrids with pest resistance may be able to utilize our findings to understand more thoroughly the fundamental mechanisms of root regrowth and plant compensation following corn rootworm larval injury.

For decades, producers throughout east-central Illinois have rotated corn and soybeans annually, and they seldom encountered economic densities of corn rootworm. In 1995, western corn rootworms caused severe damage to rotated corn throughout east-central Illinois, resulting in considerable economic losses. Yields on affected farms declined more than 100 bushels per acre compared with yields from the previous year. The long-term successful management of rootworms by crop rotation no longer provided a satisfactory cultural approach for the control of this insect pest in east-central Illinois. A newly evolved strain of western corn rootworms was laying eggs in soybeans, a behavior heretofore not known. This new strain of the western corn rootworm is spreading quickly across northern Indiana, southern Michigan, and western Ohio. In the fall of 1995, Dr. Eli Levine, Illinois Natural History Survey, and I began research efforts to address this problem. I initiated an on-farm research project with 20 east-central Illinois producers who had been severely affected in 1995 by this new strain of western corn rootworm. At several meetings with the producers, Dr. Kevin Steffey (entomologist with the University of Illinois), Matthew O'Neal (entomology graduate student), and I discussed project objectives, experimental design, and responsibilities of project participants. All experiments were conducted in producers' fields. One of our key objectives was to develop an effective sampling protocol and an economic threshold for growers to use in their soybean fields. After three summers of research, a sampling protocol that relied on the use of yellow-sticky traps in soybean fields and an economic threshold was delivered to producers. Our research efforts indicated that producers could sample their soybean fields with 12 yellow sticky traps in late summer and, based upon captures of western corn rootworm beetles, make more informed decisions about the use of a soil insecticide the following season. Producers in Illinois, Indiana, Michigan, and Ohio now will be able to make more informed management decisions for this devastating insect pest. The implications of this project could have significant impact on soil insecticide use across the eastern Corn Belt. I continue to direct research on the failure of crop rotation as a management strategy for corn rootworms, and I currently am evaluating the potential for different crops to be grown in rotation with corn and soybeans in an effort to disrupt the egg-laying behavior of western corn rootworms.

The unique adaptation of western corn rootworms to crop rotation has important long-term implications regarding the "best" management approach for producers. Beginning in 1996, we began to lead some efforts for the University of Illinois (in cooperation with Purdue University) in a multi-state United States Department of Agriculture (Agricultural Research Service) funded project (4-year) concerning an areawide approach to the management of corn rootworms. Because of escalating concerns regarding insecticide use, particularly the organophosphate soil insecticides, USDA is keenly interested in exploring an areawide management approach designed to reduce the overall insecticide load into the environment. A fundamental goal of this research project is to offer producers a more economically and environmentally sound approach to the management of a key insect pest of corn. In addition, a much broader segment of our society may benefit if a team-based research project such as ours delivers scientifically based recommendations that enhance environmental stewardship. Because many of the pest management problems faced by our clientele today are complex, satisfactory solutions will require the coordination of many groups in order to generate answers that have a realistic chance for implementation. This participatory research effort will continue through 2000.

Most recently, I began serving as a coordinator and facilitator for a new research-focused discussion group designed to explore novel techniques for the potential management of western corn rootworms in rotated cornfields. The discussion group is comprised of faculty from the departments of Crop Sciences and Entomology and from the Illinois Natural History Survey. Collectively, these faculty provide expertise in molecular biology, soybean breeding, insect behavior, insect ecology, and insect dispersal. Potential research objectives include the development of transgenic soybean varieties that either repel western corn rootworms from soybean fields or that have antibiotic properties against corn rootworm beetles.

Comments and Questions:

Q.: Is the resistance that developed related to tillage practice?

A.: No, I looked at tillage row spacing.

Q.: Was resistance a result of using bt corn? And for some reason the corn rootworms were avoiding it?

A.: The problem showed up some years before. This problem preceded bt corn.

Comments:

• They haven't adapted completely beyond pyrethroids. The corn rootworm is not really attracted to soybean or soybean fields (oats, alfalfa). The beetles are a strain that goes to other fields because they don't want to lay eggs in corn. If they make a mistake the offspring dies. In terms of pheromones, we have very potent pheromones (thought to be more important for communication). Producers are not very receptive to altering rotations. The first response is generally prophylactic chemical spraying. Why is the emergence of the corn rootworm greater in treated field than untreated fields? It is probably a question of whether or not insecticides with other modes of action are effective.

• IPM can lead to increased insecticide use. The first logical response of grower is to increase pesticide use, but this is not necessarily what will occur in the future. There will be other tools that will come along but it is going to take time.

• There aren't any short term remedies other than chemicals at the moment. Farmers make decisions based on advise given to them by supplier of inputs (this is real world, and how most make decisions). In terms of the scouting aspect, it is an overall operation. And farmers are calling universities. Unfortunately lots of good natural control are out there, but there are very few options right now that are readily available to growers. As to the pheromones, numerous studies have been used to disrupt mating. However, most studies are discouraging. The densities of beetles are too high in these fields and there are many different attractants.

• We actually had data for ten years about cropping systems vulnerability. We should have realized that at some point that factor would become important because if we had measurement systems, we would have been alerted to the outbreak condition before it became a regional problem of catastrophic proportions. We have to be thinking about cropping system vulnerability.

• One of the problems was the northern corn rootworm which adapted to the corn/soybean rotation as well but in a different way. The eggs remain dormant over the winter and would hatch two, three or four years later. Some thought that what we were seeing was the northern corn rootworm. However, we now know the western corn rootworm is displacing northern species. The question is, even if we have information, what could we have done?

• Sounds like we needed IPM resistance management of all the elements.

• For growers, it is very difficult to think long term. We are challenged by farmers who have the attitude that why should they care if resistance develops. They could ride the technology hard for eight to ten years. Then industry will provide a silver bullet to cure all problems. For many growers the bottom line is economics.

• What if we did projections based on what we see now in corn and pesticide use and present high risk operations to the EPA? We need to confront all agriculture with the challenge of how to invest capital in research and teach farmers to deal with upcoming issues. How are we going to deal with this as a country?

• We need to think about exposure as well as risks from toxicity. For example, if we look at the manner in which we applied granular formulations, they are applied once per year below ground and were not consumed directly.

• So the exposure is going to be water.

• Most pesticides, compared to nitrates, are water insoluble. They do not move much beyond four to five inches in the soil profile. They may not end up in groundwater. Runoff into surface water is a definite yes. They show up because of runoff, not because they are leachers.

• IPM as described doesn't rely on silver bullets. IPM involves a much larger social system.

• Do you believe the use of transgenic crops is IPM? Some university researchers feel it fits into the framework. These are pesticidal plants. Using them doesn't work when growers make decision about inputs a half year in advance; If there is no scouting, it isn't any different from the prophylactic use of pesticides. Farmers can scout for corn rootworm in fields as well as eggs in fields. Is that considered IPM? It does come closer. The essence of IPM is pest management and the management of the ecology of pests, using tools in the toolbox to disrupt the ecology of the pest.

• The second definition rules out the use of hedgerows.

• The fundamental principle of IPM is to diversify. We can, in essence, split hairs too much.

• How do we create measurement systems to take these things into account, and should we?

• This is applied natural history: how do you begin to do this? How do you bring in factors other than toxicological fate and risk, such as cultural practices and resistance. There are two questions: 1.) When do you want to include these factors? Concerning the impacts of pesticides on the environment, we might not care about resistance. And 2.) How do we include these factors in IPM?

• We are conducting a sustainable agriculture demonstration project in Tifton. I am talking about longer projects, different from IPM. What Mike's talk really said is IPM and sustainable agriculture are two different things. What concerns me is that we have done nothing except focus on pesticide reduction and reliance. I wish to address the larger issues of making agricultural sustainability improve the environment, instead of addressing the issues just because they are easy to address.

• How might we broaden the parameters of assessment systems? Most assessment systems have broader social goals.

• Don's question is an interesting one. If there is interest in risk assessment and we encounter microbial risks in the absence of pesticide use in certain cases, what do we know about those risks?

• Corn aflotoxin occurs in Nebraska. It is carefully monitored in terms of death to livestock. The damage occurs at a particular time. There are tradeoffs involving pesticide use versus microbial risk which show up in the empirical work in corn and peanuts as well as in tobacco due to drying.

• The mycotoxin literature is extensive. There are interesting relationships of one pest to another which opens them up to all sorts of diseases.

• We can do rating systems.

• We should focus on outcome measures. What are the risks of not using pesticides, not just of using pesticides.

• We will get a loss of biodiversity. For example, fire ants are a threat to schoolchildren.

• The important challenge with mycotoxins is detection. There are a lot of issues centered around detection. Obviously there are separate outcomes which is a good thing, so do we want to look at pesticide use and non-pesticide use?

• Pest management is important.

• But where is line between yields for producers and consumers concerns?

• That is an important point. Pest management systems are always changing. Changes in exogenous factors and changes in farmers sometimes help reduce risks but many times they make the problem worse. We need to track and project longer term consequence of decisions by farmers. Biologically-based prevention only works if we start early and make it robust across weather conditions.

• The problem is not exogenous but endogenous. We come as allies of plants, however, pests come in as if they were in an arms race.

• I have a question. How and when is it appropriate to bring these factors into the assessment systems? These are conceptual challenges.

• It is a question of scale. If we are looking at changes we also have to look at the cropping system level. In a couple of cases the average life expectancy of pesticide is two to three years. It becomes a management treadmill. If we are documenting resistance, then we will see shifts that will occur. How do we to put this in models and how do models help us make intelligent decisions?

• Let's think about that.

• How could we take into account whether there are any lesson to be learned, even retrospectively?

• Agriculture is unnatural, artificial. We have to recognize that it is an unnatural system and that we want to feed ourselves. If it were a natural system, nature would not produce nearly as much. My agency, ARS, would not look at synthetic pesticides. If we look at the research budget, 90% of the money now goes to alternatives. To calculate industry spending, quadruple our agency budget to just develop two new Active Ingredients. The treadmill is going to continue. We need to look for the silver bullet. We made the assumption that we had a solution but we only have solutions for two to five years. We must have some sort of feedback.

  One of the system indicators that might be useful to consider looks at the number of alternatives under a given situation to controlling pests.

• But even where there are tools in the kit, we are not using them. If we had been using the tools, we could have gotten ahead of insects changing behavior.

• Resistance results from the lack of diversity in management for a long time. I have seen numerous examples of it in agriculture. However, there are not many examples of cultural practices that have failed and this is unique. Could we have foreseen this?

• How do growers respond after a failure of management? Is there a credibility gap?

• 1995 was not a good year. Most growers were comfortable with crop rotation. Growers were certainly not happy in 1995. After 1995, land grant university research was taken by farmers with some suspicion. The first things growers said was "give us some tools." They worried about whether we were delivering good information. They responded by investing in new equipment and soil insecticide use went up. They applied insecticides and inputs to protect first year corn. Farmers were not looking into future as we were.

• There is some sort of Jurassic Park analogy. To successfully avoid resistance you have to have lots of options and measures and use all of them.

• How do we actually measure and use this? Can we focus on some critical components and pests? We need to assess programs or systems of management based on resources. We need assessments which consider all options and not just rely on one tool or system.

• We have put in a resistance factor into our index. We have a fairly decent database in which we could incorporate a resistance index showing interactions.

• Is that viable? What about ecosystem stability? There are a lot of instances where pests move to new crops and start eating. Ecosystem stability is really complicated.

• In applying the IPM measurement system we developed, we compared diversity in agriculture where farmers were largely reliant on pesticides and systems where they are not as reliant. This suggests the measure for diversity of tools brought to bear on pests.

• Is Eric's index viable?

• Building resistance into an index can be done. Viability is important when we build an index. So is robustness and diversity of measures.

• We need to not only evaluate the systems by pesticide indicators but also by other factors such as diversity and we have to show stability of system.

• There are a lot of solutions out there but we are not continually monitoring them. Information is not coming back fast enough. Information, in fact, is insensitive and untimely. We can use thresholds as an early warning before a crisis develops.

• Our threshold are not specifically designed for that. It is ultimately up to grower to make decisions about the use of alternatives.

• Was this a case where you didn't actively go out and look at the infestation until it was already too late?

• We have been out in the fields since the early nineties. But there was not a severe situation, i.e. a severe ecological problem. Then in 1995 we really looked at the problem. A small problem that was first county wide just expanded to other regions.

• If we had known the resistance problem would spread, was there a way to tell farmers there was a risk? Could there have been a way to give them a sense that risk was going to go up? We need to think about it.

• Following up on Eric's idea of index of resistance and genetic change, we need to consider whether the mode of action of resistance development involves effects that are single genes or multiple genes. It is an issue of genetic change and selection pressure. Selection pressure is related to farm level management. We can't just look at the chemical itself, but must consider how it is being used.