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I once thought that the term or acronym IPDM, integrated pest damage management, was significantly more realistic than IPM, integrated pest management. IPM is an acronym that has been used so much in entomology and agriculture that it now has its own connotations. "Integrated control", "pest management", and "integrated pest management" are used synonymously and somewhat indiscriminately and interchangeably. The things "integrated" are usually biological, cultural, and chemical control techniques, but this usually means making combinations of these three types of actions. The generally agreed (Oka 1979) but inappropriate goal is to keep pest populations at such low levels that they remain economically unimportant. A desirable focus is on "economic importance" of a total production system rather than on "pest population", a non-trivial shift. Within IPM circles, a phrase used is the "economic injury level", but this compounds the confusion because of the breadth of definitions of all three words. It symbolizes the threshold of pest population density above which control action is necessary. Some would seek to reduce the density. Action taken may do just that, but the suggestion of this chapter is: develop a comprehensive, mixed strategy, a total production system that achieves the objectives of the producer. Maybe killing an insect or so, part of the forest fauna, will be part of that strategy. It does not have to be, as will be seen.
It is difficult to find agreement on a definition to IPM, but it usually implies using various means for controlling insects, not only several insecticides, to get synergistic effects. It includes using biological controls (e.g., viruses and bacteria, parasites, predators), traps with attractants, behavioral chemicals, sterile male release techniques, cultural controls, managerial techniques, prevention, genetic resistance, etc.
The reader needs to discriminate between pest management (in which I contend most forest faunal resource system managers have little interest) and damage management. The difference in words is not a mere professorial distinction. The emphasis is on profit, or net present discounted returns, not on killing "bugs" or larger things called pests. Most thoughtful entomologists can make populations of insects increase or decrease. The question is: what effect does such change and its costs have on the system objectives, the dominant one being profit.
The IPM vs. IPDM contest (not an academic word game) is centered on the difference between injury and damage. For example, a beaver (Castor) chews the base of fruit trees on the grounds of a corporate headquarters. Is the beaver a pest? If it caused injury, the physical sign of change in a plant or animal, then the answer is maybe. Was the change sufficient to cause monetary or related loss beyond a threshold? If not, then damage did not occur. Perhaps the beaver's tooth marks enhanced the interest in the site for visitors. If no change in apple production occurred, then no damage occurred. If there was 20 percent reduction in the pounds of apples produced and the apples were never harvested anyway (they being from landscape and wildlife trees), then no damage occurred. If the longevity was reduced, then a careful analysis of discounting the expected annual benefits from the trees over an expected production longevity of 30-50 years would have to be done. The difference is likely to be so small that the average rational investor could not discriminate between the trees with and without the beaver's influence. Oversimplified, damage is injury plus significant value loss.
Beavers may be irrelevant to some people. The parallels for that instructional example are, hopefully, relevant to real, large-area, conspicuous forest problems. These include Douglas-fir tussock moth, the spruce budworms, southern pine beetles, mountain pine beetle, Douglas-fir beetles, fir engraver, balsam woolly aphid, larch casebearer, oak leaf roller moth, Archips semiferdnus, gypsy moth, and red-pine scale. Many trees occur on inaccessible areas with difficult or impossible-to-work terrain (the very reason that trees remain or exist in some areas). Others grow on public areas, legally inaccessible. Much wood of insect-attacked trees is not taken to market, literally that from thousands of hectares. Is this injury or damage to these trees? To the forest? To the owner? Are expenditures for insect population suppression justified on such areas? In particular cases it is justified because of proximity phenomena. Each area needs to be evaluated separately but, in general, any treatment to control insects can be argued to be undesirable because the tree wood would never enter a market even if there were no insect attacks. Actions depend on net difference in profit or social welfare (or other complex objective) from the landowner enterprise, the total production system, not the forest or the tree itself, as a result of insects, suppressed insects or other fauna.
The faunal system manager can see a role in such an analysis, for it obviates his or her conventional "stop spraying" stance and argues for rational participation in group efforts for articulating costs and benefits. It does not require arguing for wildlife, or against insecticides, only against ineffective use of limited funds to make profits or produce other benefits from forests.
IPDM becomes a system for managing damage as a subsystem of a larger production system. If the corporation puts wire around the base of all trees in the yard of the headquarters, does it manage the beaver? I think it manages the damage, not the beaver. There may be (and probably will be) no noticeable change in the beaver population as a result of protecting the trees. In some situations, so-called pest injury enhances resource value. This is true in the grain and the appearance of some woods. Injury often causes increased sap flow and fruit production. Injury may enhance environments for birds and their forage. Everything is relative. Their relativeness is in whether (a) the values lost within the total system (the one named in the context of the system) and the costs of attempted analyses and control to things called "pests" exceed (b) the values gained.
I once thought IPDM could be limited to studying and manipulating insects or other fauna. Minor reflection showed my error because insects and plant diseases are inseparable. The beetle and fungus relations of the Dutch elm disease are a conspicuous example, but there are others of such complex and varied relations as to suggest an n-dimensional kaleidoscope of color, interaction, and change. To be insect-specific in IPDM is to deny the concept of "integrated." IPDM is much more than a simple change, more than adding methods. It may be possible to reduce an insect population and get a reduction in a plant fungal disease. If I use a fungicide and get the same results, did I manage a pest? A disease? Did I "manage" at all if the treatment cost more than the expected annual loss? I suspect not.
Insects themselves are highly related. Conspicuous predator-prey relations exists, but control may be sought for all phytophygous forms. IPDM thus is a planned program to influence the effects of several species simultaneously on system objectives, not just one target species.
We live in a forested world full of things eating and injuring things in which we are interested. A landowner awaiting a wood sale cannot be pleased with seeing growth or wood quality reduced. The usual reaction is: Something must be done! Herein, the question is raised: Are you sure? The question is merely the healthy skepticism of a practical, applied manager, aware that world decisions are usually made in monetary terms. One company judged its animal damage costs to be about $0.50 per acre ($1.23 per ha). Over millions of acres, the amount becomes impressively large, but large is relative and it can be only judged in comparison with corporate profits, growth rate, competition, and even losses from other resources. As usual, the question will be put: What are feasible costs for reducing $1 million in losses? The answer will not always be, as intuition may proclaim: less than $1 million.
Globally, even with modern advances, pests are estimated to destroy about one-third of the human food, feed, and fiber produced (Joyce 1980). The harsh reality remaining since 1973 is that:
... in spite of significant advances in pest control technology, we have not really resolved a single major forest insect or disease problem in the United States.... We have fewer weapons in our arsenal ... and we have some doubts as to whether we have even put our finger on the most critical insects and diseases (Waters 1973).
Forest losses to people from fauna include those to seeds; seedling girdling; seed consumption; bark stripping by bears, elk, and porcupine; and defoliation (slowed growth) by insects; reduction in maple sap production; root damage; and more. They include fire hazard increases; increased risks of limb-fall at recreational sites; destruction of facilities; failure to flower or pollinate; even costs of cleanup from falling sap and fras. They include insect effects on wildlife, pesky mosquitoes, and gnats that destroy quality-of-time afield, and the vectors that offer people disease threats.
The needs to do something about pests are fairly conspicuous. The needs for IPDM have emerged because of awareness of the consequences of past and planned pest control work. The needs are due to:
Wildlife community observers have made lists of concerns about pesticide use. If any one out of the following long list of actual or potential concerns is legitimate, then taking alternative strategies seem to be a good idea. The problem is messy because there are real value differences for those protecting animals and those marketing control substances and methods. A dialectic may exist within individuals! There are site differences; each ecological situation is unique; objectives of most owners are not well developed; shifts in communities may occur after a pesticide has been used - detrimental to some interests, beneficial to others. Often overlooked is the simple harsh reality that even though action is rational and clearly justified, there may not be the capital available to do the work. The list suggests the dimensions of concern (not necessarily the proof of problems), the complexity, and the reasons for pressures that now grow for IPDM. Of course, the following list of concerns about pesticide use begs for definitive research.
Energy Flow
Plants
Water and Watersheds
Animals
I suspect that serious, comprehensive analyses of the long-term monetary value of a species (or life group in a particular community) will produce results that can stand favorably in monetary comparisons with other commodities or resources. Compensation for losses and damages resulting from damage control activity may now be appropriate. If they cannot, they should not.
Increasingly, IPDM becomes less and less meaningful to me (but at least it is an improvement over the more limited IPM concept) for it is rapidly replaced by a straightforward, old-timey concept of a production system. The concept of a "pest" disappears. (A deer one second before the hunting season opens may be a twig-consuming, profit-reducing "orchard maggot," and in the next second an economic boon to the county and its recreational and tourist industry.) The word pest need never be used. Insects, disease, even "vertebrate pests" (e.g., beaver on trees, deer on plantations, birds on seeds and fruits, poisonous snakes, bears clawing park signs and breaking beehives, predators of various species on livestock) all disappear, because they are merely agents of potential loss or gain. The danger of such generalization and elimination of "pests" as a pointer is that managers and control agents begin to feel some loss of identity. They have few old categories of knowledge to which they can relate. The change suggested here (i.e., extreme emphasis on a production system; dropping IPM) I pessimistically accept, will never come, so there is no real danger to those who have bought-in on IPM. A real danger, however, is the substantial loss to humankind from failing to look at forest systems, faunal and other subsystems, or other production systems as just that: production systems. "What is to be produced?" is the question pushed into view (or smashed through the grate) by the awareness.
We might define profit for the forest landowner (or person responsible for other resource systems) as net present value return and assume this is what is to be maximized (subject to some constraints like not exceeding budgets, not breaking laws, stabilizing a work force, not using more land than is available, not passing certain tax-advantage thresholds, not liquidating, etc.). We realize this should be done over time, say some 5-year period, but all forest faunal systems work must be done at a planning horizon of 50 years or more, just because of the growth rate of trees and when the effects of forest regeneration and cultivation (improvement) activities show up in the tree harvest. The significance of mentioning time is that all costs need to be considered and treated by the rational systems manager as "bankable." Call it an investment mentality and narrow, if needed, but it is a starting place. Time becomes as important an element of the pest equation as losses or gains.
By example: Some spray equipment costs $500 and I shall use it for 5 years. I could put $500 in the bank for 5 years at 6% and have $669 at the end of that time (and a rusty old machine). Is it rational to spend? Will I have more gains for my total system after spending and using the equipment than I would if I put the money in the bank? (See CAP99).
Where t is the investment period (as 5 years in the above example), the equation for the real pattern of the faunal manager, that of discounting, is:
Vo = Vt / (1.0 + r)t
This concept and procedure brings the investor, the manager, up short in the present. After estimating what you are likely to have in the future, in some situation, say $5000 after 20 years, the manager asks about what he or she would have to bank today (say at 6% interest) to get that amount? What must be the investment in the present? The answer is:
Vo = Vn / (1.0 + r)t
Vo = 5000 / (1.06)20
Vo = $1559
The present value of $5000 under the stated conditions is $1559. The procedure allows reasonably realistic preliminary comparisons to be made among expected present returns by decision-makers. See CAP5003.
The production system may be seen as one producing profit. It may not be a faunal resource system, but the concept is the same. The concept of a resource needs to be recalled, for it too is a net concept. The faunal resource manager may participate as effectively (and increasingly more effectively) in the production system by reducing losses as by increasing gains. The connotations of yield or "gains" are positive and have held wildlife managers in their force field. There is no difference in losses and gains as factors; they are the things that the manager can modify in the equation:
Production = Yield - Losses
Production implies desired ends. Here I limit such ends to "profit" but the objective can be re-shaped, as in Chapter 4 on objectives, where a modified benefit-to-cost-ratio is suggested.
The profits desired are from total systems - the farm, the forest, the factory, the city. A farm or forest (a decision-maker-controlled-entity) is the usual managerial system. For example, to talk about "farm woodlot management" is silly because that tract of the farm is only going to be treated within the context of the total farm economic situation. Action one year may be quite different than that in the next, not because of new knowledge of timber marking, new harvest strategies, or a new inventory, but because of the wife's sickness or the commitment of all available funds to a new irrigation system.
Orchard injury from elk or deer may be equal in 2 years, but in one it is viewed as injury, another damage, because of the overall ranch profit-loss situation and effects of external forces on that situation such as tax law change.
The perceptive manager will realize that working with a production system concept may allow free, open, unbiased participation in the larger decision system rather than requiring an anti-pesticide-use or wildlife- preservation stance. It invites all to participate equally and in any possible way because the objective is clear. All that is needed is to increase the gains, or decrease the losses, and to think and to decrease the net losses. Changing both may be needed, and the key concept is: simultaneously. The beauty of this small production equation is that it increases the manager's flexibility ... but also the challenges.
The production system can be formulated as a multicrop, multiproduct system. Faunal resource benefits (pollination service, recreation, game, etc.) are among the more familiar crops such as hay, grains, fruits, etc. Costs are separated from benefits because money investments take multiple roles. They may produce several benefits in different areas. Attempting to partition costs to small projects and activities in natural resource systems is silly (and makes accountants who insist on it appear that way and managers who succeed in satisfying them get lieing-induced stress symptoms). A tractor, computer, or chain saw, as examples, each involve one-cost with extremely varied purposes and uses that are creative, productive, and maintenance-oriented. A chain saw, for example, is an investment that can produce injuries and hospital costs as well as prevent accidents and their losses.
The gains are the sum of the expected values (1.0 - q) of each processed product, p; q, being the probability of failure; times the units produced per area, k; unit of land, a; and all discounted over a reasonable period, say 30 years, partially because of owner life expectancy, partially because of nearly meaningless computational results if a longer period is used.
Because products can enhance the expected value of each other (e.g., sale of firewood with vegetables; hunting sites and recreational summer fishing) an enhancement matrix, M, of multipliers might be used.
Land value enhancement, N, is added as a separate type of benefit. It emphasizes the land value component of the cost dimension. Land value, at least current minimum potential market sale value (if not actual mortgage cost), unfortunately, is not included in many analyses of resource production systems.
The system benefits, B, from all n "crop" or commodity types are:
B = (p(1-q)katMN) / (1.0 + r)t
Each of the components are fertile fields of work and the faunal resource system manager may participate in working with any of them since, as in animal energy budgeting systems, a kilocalorie is a kilocalorie whether eaten by an animal or not lost to a chilling wind. "A penny saved is a penny earned" has a familiar ring. The manager might (1) increase expected value (reduce risk of failure, q), (2) diversify crops or commodities (add a wildlife component to the corporate or forest mix; increase N), (3) increase product value, p, by advertising or education, (4) increase production per unit area by soil-water-sunlight optimization, and (5) optimize allocation of space to each commodity and/or seek purchase, rental, trade, or sale to optimize the area held. The permutations for managerial action using these few simple options (5! or 120, see CAP2026) is wondrous to contemplate (and storage, marketing, or cost reductions have not yet been considered).
If great gains were made in the above, say 20 percent improvement, would this allow increased tolerance for losses? By certain systems criteria such as progress from a base line condition, I think it should. In most cases, the more people get, the more they want. Feedback mechanisms and constraints can be used to avoid some problems of working with the interactions of benefits and costs. In general, the hypothesis would be that for the small-system decision-maker, increases in gains would increase tolerance for losses.
A rarely used concept, but one of great value, is that of the greatest possible production known. Estimates can be made of them using local water and energy constraints, observed maxima, and trends. Following their computation, comparisons of actual output of a system with the maximum can provide (1) constraints on investments, and (2) a more reasonable basis for estimating relative losses or reductions than past performance. Maximum production may be 100 units but a manager who claims having "doubled production" (from 2 up to 4 units) may be devious.
The manager must add his or her own managerial costs to the system. Even public agents should factor their equivalent salary and overhead hours into such systems. If the service and advice were not provided, it would have to be acquired. (The worth of different quality of advice may, thereby, eventually be able to be judged.) The managerial costs of observing a problem situation before, during, and after taking action must be included in a rational analysis. Every situation is unique; to treat it as average, will, on average, produce suboptimal results, namely, excessive long-term costs and less than desired changes in benefits. John V. Beck claimed that this observation is a major factor in properly estimating pest damage and control costs.
It is essential to look more closely at the meaning of costs and gains. The "economic threshold level" in the literature of IPM is a number of pests, a density. Headley (1972) refined the concept as: "... the pest population level where the marginal cost of control is equal to the marginal value of the product of control" (cf. Stern and Smith 1959, Stern 1973). This is a powerful phrasing of the problem for it specifies the population density that is maximizing. (To cause the population to decrease below this level or cause it to increase above this level will reduce net crop revenue.)
It is possible to ignore the threshold concept completely if damage is used. The point is to reject focusing on the pest population and to start giving attention to the objective-directed comprehensive system. Replacing the economic threshold, which is a population density, should be "estimated maximum expected present net value or its equivalent." Once this criterion is established, then the entire array of potential actions may be evaluated to discover the set and sequence of actions that will give, over time, the appropriately balanced returns and costs. Since neither of these can be known, they must be handled with probability estimates, thus, the reason for including "estimated" and "expected" in the criterion. There are few independent factors in the pest damage or agroecosystem world. Most factors are at least a function of what was done last year. In forestry, as with nut and fruit crops, the long-term and prior-effect phenomena are conspicuous. Dynamic programming can be especially useful in describing this production. There are too many action options in the production system, too many in the loss--reduction component alone, to focus attention upon suppressing insect density. Density suppression may be one thing to do, but a hasty decision about it is likely to produce suboptimal results. The most cost-effective system will not have been created or operated and this will be able to be shown. Eventually, owners and the public will ask for such analyses and accounting comparisons. "Why not optimum?" they will ask. How far from optimum is current practice? What is the squared deviation? Why so large?
There may be good reasons for a large deviation between the desired system and the one actually achieved. Working with expected values is the nature of natural resource decisions. There is always uncertainty. There are risks. The power of the systems approach is that these can be analyzed, risk estimates improved, and sensitivity tested. Such a test, for example, might conclude that if the interest rate on money varied from 6 to 10 percent, the solution would remain the same. There is no assurance that the rate will remain the same but it certainly provides confidence in which solution to select. If the interest rate changes to 12, after a pest damage management program has been implemented, then the manager will be wrong, demonstrably suboptimum. Such a manager, armed with the analyses and the rationale for the decision, is likely to be praised, not fired.
The sad news for the forest system owner is that unless objectives are clarified (or changed) and fundamental changes are made in the forest and its use, production or profits will not be maximum. Costs will continue. The manager must face the reality of maintenance, the long, erosive, wearing, frustrating, on-going periodic cost. The manager dealing with problems called pest-related is as much as anyone working in the forest system in tune with entropy. All managers are or should be. The pest specialist is where "... moth and rust doth corrupt." Entropy is the cloud under which the forest manager lives. It is, however, the bright banner of the person or group (the control specialists) making a living by helping others slow the entropy.
The other costs, for capital equipment as well as expendables, periodic labor, marketing, sales, protection, etc., are all added to the cost expression and each, depending on its frequence and duration, present- discounted and added. The cost of land is added. It is a complicated procedure but not very complex and needs only elementary computer work to devise at least a rudimentary system, one highly useful for aiding in accounting and decision-making.
The faunal system manager will recognize conventional pest control roles in reducing losses, predator control, use of bird repellents, and fencing. The faunal resource system person will adopt the system as the thing to manage, ignore the old boundaries, and work for the objective. The emphasis will likely be on the cost-loss component of the equation. By such emphasis, far greater social good over the long run can be had than by continuing emphasis on the yield component of the production equation.
There is a peculiar concept of IPM that has slipped into the conference halls and literature, unnoticed. It is an example of the same word(s) having several meanings. In this case, they are closely related but could result in opposing actions. The concept is of managing all of the insects of a forest, continuously. One person manages trees, another the insects, another the waters, etc. "To work with all of the insects...continuously" sounds like "integrated." Since many insects can become pests, the jump is not great to IPM. No surprise, I think such a jump is not desirable.
Forest insects can be managed as a system (cf. Graham 1959). They can be a dominant forest faunal system. They can be managed for collectors (as bird watchers collect a lifelist), for beauty (as butterflies), for food for many other fauna, as pollinators, as a nutrient recharge and slash removal mechanism in decomposition processes, obviously as a means of reducing pest-related costs, and as a distributor of the financially significant mycorrhizae. Whether made to increase (+), decrease (-), or stabilize (0) by the manager is almost a value-free decision. The same knowledge of the insects, their relations, structure, dynamics, and life history must be known, no matter what the decided rate of change. Though more difficult, it is the working hypothesis of the systems person that over a brief period, say 10 years, and surely over the long run (greater than 200 years), it will be more effective to manage a system of many insects (an effort to manage them all) than to attack species-specific problems as they arise. It seems likely that within total system studies, by concentrating on aggregate changes in the specific nominal resource (e.g., likely 5-year median increased air-dry interior wood weight sale dollars FOB), then progress can be made in understanding the major equifinal insect-controlled pathways to desired ends. These have to provide society greater returns than emergency-inspired, high-risk, high-start-up-cost actions irregularly applied.
A perspective of an insect resource system may be taken and fully justified by managers. Another perspective is that of a comprehensive forester asking for an insect system expert to advise on each particular problem as it arises. Another is of a member of a forest production system staff bringing full costs and benefits from the insect subsystem to every decision for the optimum forest. Perhaps all are needed for we seek to see the whole and to shape it.
Vertebrate Pest Programs
Abolishing the phrase IPM, and now even "integrated pest damage management," and substituting "faunal resource production system" is a difficult step to take. It is a right-footed start in a world that starts marching on its left. Unless a person is antibiotic, there is little reason for "managing" pests, a euphemism for "reducing" pests. Rarely will we consider increasing them (as we ought to for food for the insectivores that we want within the forest). The need is to manage the system production, a net returns concept. If costs or losses are significantly reduced (for example), pests can increase without causing perceptible damage.
"How do I control deer?" is the usual form of a question from the forester. Depending on the situation, I may give a quick and meaningless answer to an almost meaningless question. However, I recommend stopping at some realistic stage of the following analysis (because people run out of time, money, etc.). At least, the forest-faunal system manager needs to know that the pest subsystem can be analyzed, that it should be and that he or she should feel a little guilt when it is not because, if not, the solution provided will be suboptimum.
Comedians amuse audiences with fly paper. Getting unstuck is to get stuck. People who see a creature as a "pest" are about as funny. There is no escape. On the other hand, exterminators capitalize on the concept, laughing on the way to their bank.
In the forests, vertebrates can be genuine pests and can create danger. Losses are said to be in the millions of dollars annually but there has been no systems analysis of net benefits for control costs when combined with high secondary-effect costs. Injury (e.g., browsing) often cannot be translated as damage because there is no significant difference in the crop tree harvest (quantity or quality) but especially computed profit from areas on which control costs are incurred and those where they are not. Prevention of loss, the most cost-effective strategy, is difficult to present to skeptics because the proof is in the lack of evidence. Controlled experiments are rare for who will readily agree to be in the non-treated area, the one against which reduced losses are compared?
When a bear from the forest raided the beehives last night, there is an immediate problem and the detailed analysis suggested next herein probably sounds silly, but it is presented for demonstration. It is an excessive analysis for a problem that needs to be solved immediately. Too often, inaction is justified on the grounds "that it might set a precedent." After immediate action (and I do recommend that on practical grounds), then there is need to revise the system that is in place so that the problem, usually a symptom of an inadequate system, will not recur.
First, what might be done?
At least there are some options for immediate, "therapeutic" action. Taking such action is almost essential to retain public or client support and a positive attitude toward the professional forest faunal system manager.
There is utility in such problem events for, when monitored, their reduction over time may be evidence of the faunal manager's work. Without monitoring, assertions of influence, the effectiveness of a total system (outlined next), may be all that is possible. Proving managerial influence by asserting that there are no problems is not likely to be well received.
After appeasing the beehive owner, the system may be addressed. Perhaps one needs to be created (as follows) or some part of it outlined. Before a system can be designed to reduce black bear (Ursus americanus) damage to beehives, some general concept need to be advanced. First, the system's context is the world honey market and the world bear resource. The world honey market is far from a free state. It is highly subsidized and influenced by import and export tariffs and regulations of a wide variety. There has been futures trading in honey and sugar. Knowing current and likely future honey prices and factors influencing them are essential to systems design.
A preliminary expression of the objective of the system for the beehive owner may be a useful example. The system designer needs to remember the objective needs to be modified for a honey cooperative, a honey buyer, a regional or national government. Let us assume that the objective is "to maximize sufficient profit." We symbolize profit as D and then the perfect condition of the system as D* and specify that D * > D1 the lower limit of acceptability or sufficiency and also that D* < D2, is the upper limit. We use D* as the symbol for the index to the desired performance of the system. We decided on "sufficient profit." (It may differ in other situations, usually including more constraints. Such a constraint might be perpetuating beekeeping because of family history.) Sufficient profit may seem unusual but "maximum profit" is rarely an objective for reasons of planned gradual expansion, tax considerations, and others. "Sufficient" is expressed as "between D1 and D2." For example, the lower limit D1 is usually set at the riskless conventional bank savings rate. It is just irrational to spend money (invest it) if you are not going to make at least the bank rate. If in doubt, put money in insured bank savings!
The upper limit may not be set. Perhaps it is to maximize profit, thus D2 = D*. Usually there is a limit. The expression is usually made by an owner that he or she needs some amount as profit. In some cases it is a specific amount, but rarely. I usually hear or sense the amount as: "I need between D1 and D2." I also hear an amount, then "plus or minus 4 or 5 percent." I believe that persistent questioning will reveal, perhaps surprisingly, that very few people will make a sharp expression. Most will give a broad zone. The reason for noting this is that it is absolutely fundamental knowledge, most basic, in designing a system. It is very easy to over-design a system. If an owner can hardly define a "ball-park," it is not yet time to quibble over whether the ball was thrown across the plate. To achieve control over costs to a system produced by pests, it is essential to have a clear, reasonable objective. Just any amount of profit or control will not do. If it will, then any system will do; a non-system will suffice. An objective is needed!
Once sufficient profit, D*, is seen as the system objective, then it is possible to symbolize product yield (e.g., pounds of processed and packaged honey) as Y and since there are various colors and qualities of honey, we can specify all n qualities, each as YL(since L goes from 1 to n.) YL is the pounds of the Lth quality. Price, P, is the price per unit (e.g., a pound) but price varies with quality so we designate each price as PL. From basic economics we remember that price is a function of supply, S. We can say that price is influenced by some supply force called S*. We define supply here simply as:
S* = 1/CY
Where Y is yield and C is a proportion reflecting the part of Y that is really influential. When C is equal to 0.001 and Y is 1000, then S* = 1/1 = 1.0 and the price remains the same. When Y is reduced to 900 units, then S* = 1.1 resulting in a price increase of 1.1 times or 10 percent. C needs to be studied for each commodity and area. It can be estimated and then used in a simulation to (a) discover a range of feasible values and (b) a range of consequences. In some situations, C may not be straight-line and may take on some exponential form such as C* = C1.2 implying that price goes up at an increasing rate as supply diminishes - a plausible situation.
Thus we can summarize the production part of the profit equation as:
Production = Yi PL S*
It is hard to remember that cost functions in the profit equation just as does production as in:
Production = Yield - Costs.
Yield is the more conspicuous element but when gains become increasingly difficult and more energy expensive, it soon becomes easier to increase profits by reducing cost-and-loss then by increasing yield. This realization must come over the newsy hoopla of inventions, hybrids, and quotas-met. Reducing losses by 10 percent may result in a 2 to 3 percent gain in profits whereas annual production increases over 1 to 2 percent are rare. Defining "profit" as the objective helps begin creating a simple model as above with production and costs.
With production out of the way, costs can be addressed. It is strangely difficult to find reports of costs, even of gross monetary returns, almost as if yield was of singular interest. Seeing all of the dimensions is important for calculation but ... most importantly ... the dimensions are the places on which the manager can work. They are the avenues of opportunity to be worked separately or simultaneously. Each letter in the equation symbolizes a managerial door to be opened, a pathway to be explored for options and creative stimuli.
The cost component of the profit equation seems more straight forward than that of production. It includes direct and indirect expenditures including rent, other overhead, labor, equipment, salaries, travel, etc. Often omitted is the control cost itself; more often, the managerial costs.
A "with and without" comparison of profits is not a bad idea. Doing present-discounting is logical (but not shown here). It is the equivalent of asking about the value of planting trees or putting money in a bank. Investing in damage control or even a control report is an investment that may "save thousands of dollars" (translated, this means yield). Deciding on the effectiveness of the system remains to be done.
Assume that in one year the price of honey bottoms out, i.e., it is judged almost worthless (because of consumer tastes, demand, supplies stored, new substitutes, health scares, production, etc.; any or all simultaneously ... it makes no difference).
Some beekeeper may realize that there is no way to make a profit in his or her situation. Costs, even counting family labor as zero (an absurdity), force net monetary gains below the value D1 or sufficient income. Then comes the bear! Did damage occur?
I think not. Injury occurred, not damage. Injury is undesirable physical change. Damage results when significant monetary loss occurs (when D* < D1 or D* > D2. D* being outside these limits may suggest high profits in the honey subsystem causing tax or other imbalances elsewhere. The limits are significant! Damage is a concept of system performance, not animal activity.
The bear-bee system is far from a closed system. It ranges among and is as expansive as low-sulfur coal availability affecting the price of steel suitable for bear traps, price supports for honey, the sugar cartel, bear hunting regulations, urbanization and its influence on keeping packs of hunting dogs, and the regional use of pesticides affecting bees.
These are listed to point to the potential dimensions for understanding the system, modeling it, and thereby having an information base for rational decisions about expected production, price, and production costs and, of course, risks of failure (for these estimates are needed to compute "expectancy"; Chapter 4.) I imagine only a few individuals developing such a system. Its development cost would have to be added to the cost side of the profit equation...thus probably no profit. However, a small management group working with such a system for dispersed beekeepers throughout a region seems likely to be cost effective. Its role would be in providing advice, buying in quantity, processing economically, marketing in volume, influencing legislation...and, yes, influencing, if needed, the number and behavior of potential pest species. The use of the bear-bee system by any individual would be infrequent, perhaps a few times a year. Defying one of the rules of computer use (abundant repetitive use), it is consistent with other rules of use (singular, high-value or critical information output and many users).
Without a system to help understand the game and to keep an account of the players and the plays (compared to the frequent occurrence in a simple game with 4 players of someone saying "what was your bid?" "What was the last card played?") then the honey-profit producer is not playing to win. There seems to be a strategy of merely staying in the game.
"Staying in the game" is an objective. A system can be devised to achieve that objective. I recommend to managers to make attempts to be value-free about public objectives, trying not to emphasize one over another or to suggest which ones are good. (They should have their own, gladly tell them, but their role is to have objectives articulated by their clients, corporation directors, regional leaders, or the general public, and then create systems employing those objectives.)
Grossly staying in the honey-producing business is very easy, for it is readily subsidized by other family members and farm work. Lands, rent, stoves, energy, warehouse, sugar substitutes in bad years, etc. all make detailed analyses difficult but make managerial decisions easy. Almost any actions will be sufficient. The honey business is a very gross system; nicely put, very robust.
The systems analyst and designer now recognizes that the bear-bee system has many parts, most of which can be shaped, influenced, or directly changed. To manage a pest is absurd. To act as if doing so requires pretending that only one out of 20 factors is influential and that being so, changes can be made sufficient to move D* within the range of D1 and D2. A roulette play is more rational!
The requirement is to manage the entire honey-for-profit system. This may be a big requirement, but it is as big as "kill the bear" is small. The message for some people may be "to plan" but that is now vulgar. More clearly, there are needs for comprehensive systems that are designed and managed.
What to Do
Vertebrate pest damage varies in amount, species involved, regions, etc. Specifying what steps to take for a particular situation is very difficult and likely to be judged flawed. Computer expert systems are likely to emerge to address this complexity - much in the same way that a doctor prescribes for a patient.
Once a problem is seen, an analysis of profit is needed. Assuming damage occurs, then it is possible to estimate the amount of money that can be invested in damage management or control that will still allow a sufficient profit to be made. This amount sets the limits of the management system. The options need to be selected from a local list that may include:
LEVEL 1:
LEVEL 2:
There are many tactics useful within each of these ideas. The different levels of action are important to discriminate. Strategies and tactics for pests generally will be listed later. First, some thoughts about specific vertebrate-forest relations.
Of the requirements listed by Schubert (1977) to get natural tree regeneration in arid lands, mammals were dominant in two of them. The factors were:
He noted that the real difficulty was getting the requirements met simultaneously.
In the arid lands, ponderosa pine seeds only germinate in the summer wet period. With all of the other factors working properly and having done a full analysis of expected present net value from the regeneration subsystem, the expected value can be increased by decreasing the rodents and the browsers. Poison bait stations placed on a line 1 tree height away from seed trees or leave strips and 1 tree height apart will significantly reduce populations for the germination year. This should be combined with walk-through (or aerial) casting of grain (e.g., wheat) (at 40 lbs./acre) using a cyclone seeder. The extra seed reduces feeding pressure on the tree seed. Since natural regeneration uses seed trees and their seed cast is two times the height of trees and cuts greater than two tree heights wide are not recommended, this limited control will likely result in the 2000 trees per acre stocking needed from the 50,000 to 200,000 seeds available under favorable conditions.
It is important to use fairly direct control on large conspicuous problems because they are timely and few people will tolerate a prolonged solution, even an effective one, for a problem with an apparent immediate solution. The manager needs to gain control of the system, to educate, to set up physical situations in which direct control (e.g., snaring) is effective, to mobilize workers, to prevent problems, and to have research results on hand for effective, often very creative work.
A major problem of pest control is that in an effort to control one pest, another may be inadvertently created or an epidemic triggered. This is very true for insects and one of the main reasons for the rise of IPDM. It occurs in vertebrates as well. Suppression of white-footed mice (Peromyscus) to prevent their feeding on tree seed may allow more gypsy moth pupae to survive since these too are a food item. The modern residential environment is a fascinating example of inadvertent creation of a system nearly perfect for gypsy moths: cats that eat mice that would have eaten pupae abundant in bark flaps, litter, woodpiles, and picnic tables and in children's tree houses.
Strategies and Tactics
The number of conspicuous techniques which may be integrated in faunal systems for reducing costs and losses may be limited (Giese et al. 1975), but the following set of options, especially the permutations of these (over 10 to the exponent 90!), is enough to be impressive and discouraging in its complexity. Bankruptcy and loss of profit are the countering forces. Computer aids to selecting and designing an optimum system from among such complexity now is realistic, and for a region, corporation, or state, cost-effective. Only the owner of large areas or manager of large operations will be able to afford to develop such systems for private use. Developed, their costs can be readily distributed to users of the system(s).
Manipulate the Environment
Manipulate the Vegetation, Animals and Site
Manipulate the Population Structure, Dynamics, and Relations
Manipulate Human Values Associated with Forest, Crop, or Animal Production
Many of the above techniques are self-evident. An item may stimulate a creative solution to a unique problem. Each requires detailed study and usually consultation with experts to obtain timely information. In no way should a checklist be taken lightly. It is not presented to trivialize the enormous work and energy required to make informed decisions and efficient action in each item on the list. The list might suggest what things need to be "integrated."
Some topics are of special interest and need a few comments, but first an example:
Example
An example of integrating techniques, not just using several, is the control of understory vegetation in forests and re-growth of "weeds" in wildlife clearings created for edges and abundant forage production. Applying fertilizers in the spring can make herbicides more effective than herbicide alone. The fertilizer promotes young growth, making plants susceptible to herbicide applied soon thereafter. The union of timing, fertilization, and spraying herbicides - also with attention to spray-day conditions, spray droplet size, and herbicide and fertilizer selection for the plants on the site - can result in a highly effective and relatively low cost operation. Not just a long list of tactics, the control effort is a planned sequence of an optimum mix of actions resulting in desired consequences greater than the sum of the best singular actions or the sum of a random sequence of actions.
The benefits of herbicide work in forests, and especially on regeneration, include changes in availability of water and nutrients to trees, reduced frost risk, and depending on species and site, presence of insects, rodents, and disease. Some growth is so dense as to restrict carbon dioxide availability to plants. Positive effects of the vegetation include protection from mechanical and snow injuries and modified surface water losses and dew collection. All of these need to be included in the analysis of what should be done on each site. Each site demands its own unique analysis of net consequence per unit of cost. Such a suggestion would once have been judged infeasible. Now it is highly feasible, at least at rudimentary levels, using a small computer. Pesticide selection can be made using a simple set of weighted objectives and a list of available or potential substances. A list of representative objectives is shown in Table 11.1.
These can be weighted. The effectiveness of each substance in meeting each objective can be quickly estimated by local experts or done, laboriously, from the literature. Some objectives are not included in things manufacturers must report, so rough, relative estimates must be made. This, the large number of objectives, and variable field conditions argue for a quick, robust approach. Objective weighting procedures (Chapter 4 and CAP685) can then be used to select the optimum substance. This is only one step, but it demonstrates the relative ease and practicality of stepping through a problem, solving each subsystem, and unifying ideas of when to apply a selected substance (if at all, because expected gains may not exceed expected total, long-term costs), with what other practices and with what maintenance regime, with what planned adaptive procedures in force, not only on site, but also for the overall damage control and production system.
| Table 11.1. Potential objectives which may be listed and weighted in terms of relative importance then a pesticide selected to maximize the sum of the weighted characteristics. |
|
Insecticides: Additional Observations
Broad spectrum insecticides are cost-effective over the short run, but may be quite costly over the long run, at lease due to the periodic costs that accumulate in a present-discounting equation. This is much too formal an analysis for a problem as emotionally charged and voluminously described as the use of insecticides. It being impossible in realistic time and budgets to learn of the effects of any broad spectrum insecticide, and the objectives of societal groups being so unclear and varied, then it has been reasonable to use insecticides. Apparent costs have been low; there has been much effect on insects for relatively low costs of substance and application. There are now ample studies to show broad-spectrum long-term insecticides should be used only to treat very special problems and situations. Any substance, if grossly applied, is likely to produce undesirable effects (translated: costs). The substance is rarely the problem; its application is. Herein my recommendation is, as throughout this book: retain the managerial options. Make the list of potential tools and techniques as long as possible, then evaluate them soundly. At least use the simplistic process of weighting objectives and describing the effectiveness of each potential technique, then selecting the technique that will best perform the stated task. A very poisonous, carcinogenic substance should be retained on the list! It might never be selected for use because of the weights and alternatives, but it should not have to be discarded and might be available when a unique or special occasion may arise. Faunal system managers need not unduly heap constraints on themselves or allow it (e.g., banning all use of strychnine, 1080, and sodium and calcium cyanide as predacides). The possibility of misuse of anything exists. Preventing a few misuses (cost savings) needs to be compared to cost savings over time, over large areas, for many people. I find the situation having desirable parallels with the medical system. Very hazardous substances, both for individuals and society, are administered by regulated, highly educated, physicians and nurses. There is little difference in what could be required for those who use dangerous substances in the wildlands. This section is not a plea for relaxing controls on toxic substances in the environment. It is a request that in the future, people realize the expertise available, and that they understand there are tools that are scalpel-like, not hammer-like, that can be used by skillful pest damage control staffs. Such people exist, but more need to be educated and a situation restored so that getting such an education for this work is reasonable. There is a need for an environment for a "wildland pharmacist." Having substances is not the way to high-quality forested and other environments, but unique, prescriptive, cost-effective work is one way.
People interested in animals may disparage the use of pesticides but the homeowner who is overrun by ants or sees a raspberry crop or a prize expensive shrub disappear is likely to want immediate revenge, if not a solution to future losses. Chemicals are a fast and easy solution. Others may be irrelevant, because the plants will not be replaced. It is difficult not to emote negatively to assertions that about one-third of the potential crop production of the U.S. l is taken by disease, weed, and pest. This suggests annual mega-losses of over $20 billion. Insecticides will be used to combat these perceived losses.
A basic premise of insecticide "registration" or approval under the law for use on forest insects is that a chemical will have very similar effects on different species of the same insect. Such general effects no longer see true (Robertson and Stock 1984) and 100-fold differences occur in toxicity to genera. Later studies now suggest very great differences in toxicity within a species (Robertson and Stock 1984). Not family, genus, or species, but within species and life groups is the only reasonable basis for comparing insecticide effectiveness! Population responses are neither similar nor equal. Sibling groups, the genetic product of a single pair mating, have demonstrated highly variable toxicity to several insecticides. These are the lowest units for study of variation of population response to a forest treatment. The response differences were due to variation in frequency of an esterase isozyme detectable by electrophoresis. As a result of these studies, it now appears that routine genetic assays are needed as part of pre-treatment surveys. These assays will provide one key part to an estimator for population response to the insecticide application. Robertson and Stock (1984:10) said:
Initially, joint genetic/toxicological assessments might be performed as part of each population survey. Larvae from many randomly selected egg masses could be reared to the forth instar in the laboratory, their response to a particular insecticide determined, and survivors and control larvae from each sibling group subjected to electrophoretic analysis. Once sufficient data from concurrent genetic and toxicological evaluations were obtained, direct extrapolation from a pre-spray genetic survey to a dosage required for desired level of mortality in the field could be achieved. Ultimately, such matching could minimize overdosing and environmental contamination on one hand, and insufficient levels of control on the other.
Robertson and Stock (1984:11) reported extremely high differences in insecticide tolerances of forest insects and found these strongly related to the previous spray history of the areas. The populations exhibit resistance of a highly variable nature because exposure during these past treatments of areas confer increased tolerance to a totally different insecticide. This is called cross resistance and is manifest by enzymes that detoxify insecticides. The gene responsible for cross-resistance confers high levels of microsomal mixed function oxidase activity to individuals. They thus have more enzyme to detoxify the insecticide.
Regulations
The major ploys in the pesticide regulatory game, a game played by policymakers, not scientists (who are often confused about their proper role), is: (a) to wait until all studies are completed and human epidemiological studies based on them are complete (the extended-time-and-reduced-uncertainty ploy); and (b) to act (regulate) immediately at first evidence of a problem (the reduced-time-but-increased-uncertainty ploy). Given the certainty of uncertainty in such situations, a debate is expected to persist between those who wish to minimize risks and those who wish to receive the benefits from using a substance in a particular way. Lives saved today (e.g., by protecting foods) may be lives lost tomorrow (e.g., by carcinogenic effects). Money and person-days saved by regulation needs to be balanced against corporate losses, unemployment, taxes foregone, and research program impairment. The small system that seems easily handled - regulating use of a pesticide - can easily gain the context of a regional agro-industrial complex. The decisions need to be made with all the computer modeling and decision aids possible.
The rational player, whether operating at the forest or regional scale will be trying to maximize the expected gains (i.e., considering all of the uncertainties, r, therefore the expectancy is 1.0-r) and minimize all of the expected costs and losses resulting from an act. That act may be to apply malathion in the morning or adopt a proposed regulation tomorrow afternoon.
Decisions are rarely made once. It is imperative that decisions about regulations (or about treatment strategies) be evaluated and changed where appropriate. This is a clear feedback operation that is missing in much current practice. Changing populations, technology, knowledge about substances, alternative applications, costs, and secondary effects demand continual study of regulations (see Atkinson 1980) but these studies need to be unified with a functional or action-oriented group so that changes can be made when the studies are done.
Regulations of insecticides and other faunicides are one way to reduce costs to society and increase their effective use. Regulations serve as education and policy devices. There is a need for more general awareness among the public and producers that regulations need to be based on well- conducted, selective studies, that sufficient studies will never be done, and that the resulting uncertainty creates a game (see Chapter 17). Adopting a regulation is a move in a game, one with great uncertainty and high payoffs and very high risks and hidden costs. It is a game from which we seem unable to withdraw. The remaining option: learn to play better, together.
Time
Time is fundamental knowledge for the producer concentrating on reducing losses. Of course, it is the dominant variable in the present discounting equation discussed above. In addition, given that a species is truly producing monetary loss or preventing objectives from being achieved (a big order) then control efforts need to be carefully timed. Carter (1975) reported that there are many species of aphids on trees but only a few that disfigure them or reduce growth. They have very different life cycles.
Adelges abietis, for example, is an aphid, the life cycle of which must be precisely known if insecticide treatment is to be effective. Each treatment is short-term transitory, both because of insecticide breakdown and aphid re-invasions.
Timing is critical in trapping, using insecticide, phermones, applying cultural practices (e.g., plowing, burning residues), etc. Timeliness is the concept of being able to respond to a real problem. If every pest outbreak is termed an emergency, then no one will listen. Cry wolf. There is a need to have a select review group of scientists (not all entomologists) on call to review evidence and then, in very high risk situations, to be able to order an attack. The parallels are in forest fire fighting, hospital emergency room techniques, rights of eminent domain, and war powers laws. The present ponderous public systems and the morass of conservative responsibility-escaping committees create situations in which control efforts must be ineffective. Timeliness is essential. All pest outbreaks cannot be predicted, all are not gradual, all are not detected in large sampling programs. There will be pest emergencies. The probability of that is 0.999, maybe 1.0. When remains the question, so a reasonable response is: Whenever makes no difference. We have designed a procedure for a few reasonable people to respond immediately, based on evidence of need.
Time is often the independent variable in equations expressing change in insects per unit time. This is misleading and using it can be an intellectual suppressant. Schultz and Baldwin (1982) reported that oak leaves change drastically after they are defoliated by gypsy moths (Lymantria dispar L.). Of course, this change occurs over time (but so does everything). By attention to change in tannin, phenolics, dry matter, and toughness, they were able to provide a functional or physical basis for insect changes. They saw changes in the substances that could be toxic to the moths as well as other insects, cause reduced insect growth, and increased later nondisease mortality. The changes in replacement leaves may prevent a second defoliation in a single season. They observed:
These results indicate that the role of the host plant must be considered in studies of episodic population phenomena. Not only may reduced food quality retard pest growth, but it can also make the pests more susceptible to disease, parasites, and predators. This could explain why so many different hypotheses about the initiation and decline of outbreaks appear reasonable. The induction of lowered host quality by herbivory, followed by herbivore population decline and relaxation of plant responses could result in cyclic pest population explosions driven in part by the responses of the host plant. One important consequence is that outbreaks of pests such as the gypsy moth may normally decline under natural circumstances.
Health Risks
An enormous literature documents sufficient cause for care in using pesticides. They are selected for their ability to disrupt biological processes and to kill. It is not surprising that they do so. A reality of biology and chemistry is that almost everything in sufficient quantities is toxic. The trick in the pesticide arena is to select those substances most toxic at lowest levels to the problem organism and to use them at those levels, when necessary, under well controlled conditions. All of those conditions are rarely met so "the pesticide problem" exists.
Acute toxicity is evident. Not so evident is the toxicity that is called chronic or long-term. An example is that caused by toxaphene, a chlorinated hydrocarbon. It was found to be persistent in the environment and fish raised in its presence developed the broken-back syndrome. This, briefly, is a skeletal condition produced by the body using all of the vitamin C in the diet in detoxifying the substance and not in bone growth and development.
There are a host of pesticide effects. The effects of combinations of them have not been recorded. These include arresting development, inhibiting reproduction, suppressing feeding, stimulating mutagenic effects (usually resulting in failure to be born or hatched), stimulating carcinogenic effects (cancer-producing), and prompting behavioral disorder or nervous system change. The system manager is typically concerned that these are unacceptable secondary costs, that imbalances may lead to new problems, and that risks to other valued life are excessive.
Few people now argue that "what you don't see doesn't hurt you." Lack of signs of acute toxicity does not prove a substance or application is safe. Systems productivity over the long run seems to be a useful criterion for comparisons. Animals not present (whether killed or not produced seems a trivial distinction) seem to be a useful number. Stable species richness would seem a good criterion for the speculator, those liking future options, and those who are sensitive to the ease with which systems are upset and to the risks that accompany their rebound.
The farther a person's knowledge away from a particular field, the more general will be the observations made, the more conspicuous will be the risks and uncertainties he or she expressed. This seems true for scientists and resource managers as well as the general public. As the U.S. population becomes less rural, the apparent risks loom large indeed. The manager must work to reduce the over-inflated perception of pecticide-use risks within forests. Given cautious application of very costly substances in a recognized pest-damage situation, it is unlikely that a team of ecologists can illucidate the significant changes in any forest forest system in the world after 3 years. The manager must work diligently to overcome the losses of pests as well as losses of techniques and strategies for damage reduction due to over-inflated estimates of risk. One way to reduce these estimates is to reduce irresponsible use, get the bizarre cases under control, and reduce the cases in which high-risk tools need to be used. Licensing (e.g., PL 92-516) may be the only solution; the evidence is that education will not work; fines in the past have been neither sufficient enough to be a widespread threat or ample enough for restoring damaged ecosystems even if their use was dedicated to that end (assuming the performance measure for the restored system could be written and agreed upon).
Current control of health risks from pesticides in the U.S. seems insufficient. It makes sense to be cautious when using things that destroy life. The life not destroyed may be your own or that of your children. Pesticides end up in world water, in the atmosphere, in foods now mixed in grains and meats in world wide and variable markets. The pesticide problem is one of world public health. It demands attention because all forest faunal systems are potentially influenced by human decisions about how pesticides are or may be used.
Immigration
Aircraft and boats have opened routes for introductions of pests previously only possible by a catastrophic break in an ecological barrier. New products of all types are quickly sent around the world. There are few barriers. It is amazing that there are not more exotic pests, given the mixing of our technocultural experimentation. The gypsy moth, for example, was introduced in the U.S. in 1869 following its failure in profitable silk production. It seems reasonable to attempt to contain pests of high-value crops, to use quarantines, inspections, and fumigation to prevent the introduction of potential pest species. Pests of minor importance in one area have become pests of major importance when introduced, in some cases, because their full complement of parasites and diseases was missing.
The techniques used need to take account of the risks of losses but at the same time account for reasonable requirements of trade and to minimize bureaucratic controls and costs.
Location
Most pest and disease problems, both in number and extent (suggesting a diversity index: "perverse and diverse"), are the result of putting plants and animals in the wrong places. What does "being in the wrong place" mean? Silvics texts will list tree species and their characteristics. When a tree is planted on the wrong site, it usually means that soils are not well drained (or too well drained), temperature range too low or high within 50-100 years, winds produce excessive evapotranspiration, nutrients are inadequate or some pH-nutrient interaction produces toxic conditions or locks up foods needed for rapid growth (growth that surpasses the losses to the hordes of omnipresent foragers). 
H.J. Heikkenen has emphasized the relation of tree soil moisture to insect and disease claiming, I think rightly, that healthy, unstressed trees can defend against or overcome most insect attacks. With remarkable creativity he has unified observations and principles and shown that dying trees (those unhealthy or typically moisture-stressed when crowded) are "hit" inconspicuously. The observation of large numbers of insects typically leads others to the illogical conclusion that the insects killed the tree. Rather, he suggests, by analogy, bark beetles are akin to vultures on a carcass. The beetle no more kills a tree than a vulture kills a deer. Both animals "attack" the dead and dying. The southern pine bark beetle (and others) are detritivores or scavengers. To "control" beetles is to preserve dead wood. Better it be cut for human use as wood, left as prey-food for a variety of carnivorous creatures such as the woodpeckers, or allowed to replace nutrients and moisture holding capacity in the root zone for the next regenerated forest. Perhaps when carefully managed, areas will have species well adapted over the long run (say more than 200 years) to the abiotic extremes of the site that typically manifest themselves in moisture stress, the latter stages of which receive insect and other response. They can be harvested before bark beetles become evident. Farentinos et al. (1981) observed that tassel-eared squirrels, Sciurus aberti, ate cortical tissue of some ponderosa pine (Pinus ponderosa) twigs. They ate more from some trees than others. The trees less eaten had more alpha-pinenes than the others. This is totally consistent with Heikkenen's theory. Not a deterrent to the squirrel as suggested by Farentinos et al. (1981), the monoterpene is evidence of a dying tree (at least "highly stressed" tree, for who can specify the exact point at which any tree "dies," least of all the needle-persistent pine trees?). The squirrels eat high-energy cambium from the twigs in healthier trees in crowded stands. The monoterpenes which attract beetles and other insects are the "odor of death," a mere correlate of the state of the tree, not a squirrel repellent. There may be some repellency, since nothing in nature is singular, but this would be by pure chance for there would be no survival value in producing such substances in a dying tree.
In another system, the Alaskan boreal forest, where post-harvest and post-fire shrub growth is dense, crowding occurs, moisture available per plant is very limited, and monoterpene and resin production is high as the plants "crowd out" each other. Bryant (1981) also found that these same substances were related to low palatability of snowshoe hare (Lepus americanus) forage. Hardly created by plants as a defense against animals, these degraded sugars are the "death throe" chemicals residual in plants as they prepare to exit the forest. While total available high quality forage may well determine changes over the years in hare abundance (Chapter 7), and hares are abundant when food is abundant, and adventitious shoots which contain monoterpenes grow from browsed twigs, it is unlikely that these substances are a cause of the so-called 10-year hare cycle.
The proper place for trees needs to be determined at a regional scale as well as within the stand. High density of trees can easily result in insufficient moisture for individual trees. Stressed trees, "dying," are often attacked by insects. Similarly trees in water-logged areas can exhibit the same reactions. Stands with trees widespread have few stressed trees; crowded stands eventually with water shortages for individual or groups of trees, will emit attractive substances and the insects will appear. A tree in a well drained site with ample volume for its roots is in the right spot to avoid problems, for example the southern pine beetle problem. Skillful planting and thinning can avoid the insect problem and thus the insecticide problems encountered by the other fauna of the forest.
Resistance
Resistance of insects to control-agents is an ever-present problem and increasing. There are now at least 10 cases of resistance for every class of pesticide. The long-term insecticides have resistant species and these, in the no-predator environment, breed, further increasing the number of resistant animals.
Resistance to insecticide results, in part, from excessive use (amount, frequency, etc.). Resistance problems are an expression of failure to use multiple techniques (the perversion of "integrated" implying several insecticides) such as better regulation and enforcement, farming technology, cultural practices, carriers, additives and spray devices, combinations of substances, diverse timing and short-lived substances. Support for new and improved means for all of these are needed - both research and education. "Integrated" is a concept that needs to shift from "biological" to "multiple" to "balanced" to "optimum mix" and eventually to none of these. They can be replaced by rational production, managers seeking objectives by the lowest costs and least losses, both primary and secondary.
Color Modification
Insects appear to recognize color as well as patterns. It is not surprising that plants have adapted, i.e., retained certain pubescence, color-masking covering, or other strategies that reduce insect foraging. It seems that such perception of color can be used by managers in attracting insecticide to traps, in selecting plants, and in "coloring" plants to reduce damage (Prokopy et al. 1983). Combining knowledge of insect color perception with that of olfactory stimuli seems reasonable.
Attractants (like the red ball used to lure apple pests), reactant, repellent, stimulant, inductant, tasty, distasteful are not plant or chemical properties of plants or animals, but descriptors of reactions in context. Understanding this, using this perspective, can open many creative pathways for the faunal system manager, for the door is not closed to the manager at the organism level but opened to the environment.
Repellents and Antifeedants
Naturally occurring substances like caffeine, a methylxanthine, are repellents and in low amounts are synergists of pesticides. They appear to have a role as natural pesticides and at least are insect inhibiting. The message from nature may be that low amounts of a phosphoesterase with other compounds may be effective in insect control and thus of their damage (Nathanson 1984). The heterocyclic compounds (e.g., in deer-repelling daffodils or narcissus) seem logical subjects for study.
There are natural feeding repellents, resins, in forest regeneration that might be exploited in the future (Rehr et al. 1973). See also Coley et al. (1985) and Farentinos et al. (1981).
Some compounds release alarm behavior and thus are defensive, e.g., cyclopentyl ketones in dolichoderine ants (Wheeler et al. 1975).
Bounties
Avian and other pests have stimulated bounties. A bounty is money paid for individual pests destroyed. Examples are monies paid for heads of hawks or tails of foxes. In many studies over the years, bounties have been demonstrated as ineffective. The reasons for failure are many, but include enormous amounts of fraud, lack of effect on the offending species (e.g., all hawks), lack of change in perceived losses, rare ability to take the animal of the desired sex (usually female producers), and hunters invariably spend efforts on areas where populations are highest, not where pest-caused losses are greatest. The "bounty hunter syndrome," with parallels in welfare and educational circles, even state wildlife agencies, often emerges. The bounty hunter seeks to stabilize his or her income from bounties, certainly not to reduce a population or to solve the problem. Where bounties must be used, for political and other reasons, then they should be very high, limited to females, should increase for pregnant females, and the system needs to be policed very carefully, and a specific means to terminate the bounty needs to be stated at the beginning of the program. The costs of policing, monitoring changes, and judging effectiveness, and implementing cessation when called for should be included in cost analyses of the bounty project.
Inheritable Factors
If populations can be made reproductively isolated or incompatible, their productive capacities may be limited. Microorganisms have been demonstrated to produce nongenetic cytoplasmically inheritable factors in beetles and flies (a endosymbiont intracellular inclusion) (Wade and Stevens 1985).
Sterile Males
Much discussed, the technique has limited applicability. Male insects made sterile by radiation or chemicals are released. After breeding, the population disappears. This "sterile male technique" requires that sterile males be competitive in breeding many females, at least or more so than fertile males (not always the case) and that there be a very large number proportionately, of sterile males. Single-breeding females represents the best case; polygamy reduces the effectiveness of sterile male releases; monogamy is not essential.
Research
Research, like other aspects of the IPDM topic, can easily be turned to biological and ecological topics.
In addition to answers to these few questions there are very broad needs to provide information that enables a manager to alter or sustain a course of action toward rational production. The neo-pragmatic alternative (Chapter 6) remains a suggestion.
See possible resources within the Berryman Institute in Utah.
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