Proceedings of the Third Annual Northeastern Forest Insect Work Conference
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Proceedings of the Third Annual Northeastern Forest Insect Work Conference New Haven, Connecticut 17 -19 February 1970 U.S. D.A. FOREST SERVICE RESEARCH PAPER NE-194 1971 NORTHEASTERN FOREST EXPERIMENT STATION, UPPER DARBY, PA. FOREST SERVICE, U.S. DEPARTMENT OF AGRICULTURE WARREN T. DOOLITTLE, DIRECTOR Proceedings of the Third Annual Northeastern Forest Insect Work Conference CONTENTS INTRODUCTION-Robert W. Campbell ........................... 1 TOWARD INTEGRATED CONTROL- D. L,Collifis ...............................................................................2 POPULATION QUALITY- 7 David E. Leonard ................................................................... VERTEBRATE PREDATORS- C. H. Backner ............................................................................2 1 INVERTEBRATE PREDATORS- R. I. Sailer ..................................................................................32 PATHOGENS-Gordon R. Stairs ...........................................45 PARASITES- W.J. Tamock and I. A. Muldrew .......................................................................... 59 INSECTICIDES-Carroll Williams and Patrick Shea .............................................................................. 88 INTEGRATED CONTROL, PEST MANAGEMENT, OR PROTECTIVE POPULATION MANAGEMENT- R. W. Stark ..............................................................................1 10 INTRODUCTION by ROBERT W. CAMPBELL, USDA Forest Service, Northeastern Forest Experiment Station, Hamden, Connecticut. ANYPROGRAM of integrated control is likely to be much more expensive than complete reliance on pesticides in the short rzm, especially if we restrict our thinking to the cost of program development. Clearly, the use of pesticides was more appealing in the years before publication of The Silent Spring. Not only did our operational systems consist primarily of one- dimensional pesticidal applications, but little research effort was devoted to the development of supplemental or alternative methods. DDT seemed to be a miracle remedy; that was all one had to know or care about! Now a rising tide of public concern over possible adverse side effects of pesticides has resulted in increasing constraints on their use. And perhaps largely as a consequence of these con- straints we are now beginning to see increasing adverse effects from the pests themselves. In the face of this, it seems both re- markable and tragic that we have yet to really face up to the increasingly urgent need to produce supplemental or alternative population-management systems. Where do we go from here? First, we have to recognize that broad, flexible, and ecologically sound programs will not only cost a lot of money to develop but also that this development will take time. We then have to get this message across to a public that invariably wants action programs now! Second, we will have to plan ahead as carefully as possible. Scattered and uncoordinated research and control work usually result in find- ings that cannot be combined efficiently a posteriori to contrib- ute to problem solution. Our efforts will have to be coordinated more closely in the future than they have been in the past. TOWARD INTEGRATED CONTROL by D. L. COLLINS &L" LL wad I HAVE a suspicion that the word "integrated" is one of the most overworked and misused terms in common circulation today, including its use when coupled with the word "control" with reference to insect pests. Therefore, before devoting an entire conference to the subject of "integrated control", we might do well to see if we know what it really means. The word "integrated" is derived from the Latin adjective t,.integer", which originally meant "untouched or "entire". When converted into a verb and then, with the past tense used as an adjective again-that is, the word "integratedo-its mean- ing according to Webster is: "composed of separate parts united together to form a more complete, harmonious, or coordinated entity". For the word control we find several meanings, ranging from "power or authority to guide or manage" to "reduction or regu- lation of the wildlife population of an area by killing". Presum- ably the latter meaning conforms most closely to the interpreta- tion commonly understood in the expression "integrated control". If we substitute these definitions for the words we are de- fining, we come up with "reduction or regulation of the wildlife population of an area by killing (by use of) several separate parts united together to form a more complete, harmonious, or coordinated entity". Or, if we start fresh with the meaning of the word "integer", we would guess that integrated control would mean "complete control"-although this is not the way we usually understand it. Thus we see that the common entomological meaning and the actual etymological meaning of the term are somewhat at variance. In spite of this semantic confusion, or perhaps even because of it, the expression "integrated control" has certainly caught on with the public as well as with entomologists. How- ever, its ambiguity allows it to mean different things to differ- ent people, and therein lies a difficulty and danger. To a person confronted with an urgent pest problem, it is rather risky to recommend "integrated control", especially if you have to stay around and explain what you mean by it in terms of positive action to solve a particular problem. Yet, if we are to continue to use the expression, we must be prepared to accompany it with pertinent, useful advice. Otherwise the term becomes a fatuous subterfuge for avoiding the issue. Possibilities Historically, in forest entomology, or rather, in the control of forest insect pests, before the recent era of reliance on pesticides, the approach was basically one which we would now call "integrated". Such well-known and widely re- spected forest entomologists as S. A. Graham were empha- sizing the suppression or regulation of forest pests by atten- tion to certain biological facts and various cultural practices long before the term "integrated" began to be thrown around so loosely. Graham always emphasized means of control other than chemical, and I think we might well re- turn to his early principles and precepts in an attempt to appraise the present situation. Until recently it was thought by many persons, or at least hoped, that a control of the gypsy moth, or a way to stop its spread, could be developed in time to keep it from over- running the southern and western Appalachian forests. Hence a belated, but intensive, almost desperate, effort to learn more about it, and to try anything that seemed to offer a chance of halting its advance. At about the same time that the program of total suppression and prevention of spread began to appear hopeless, the situation was further aggra- vated by the furore about insecticides. Research on other possible control methods, which had already been under way, suddenly acquired stronger support, and many new possibilities received attention. A serendipitous result of the intensive work on gypsy moth has been the development of information that can also be applied to other forest pests as well. A review of possible control methods for this insect would certainly include the following: Release of sterile males. Sex attractant pheromones. Genetic manipulation. Parasites. Invertebrate predators. Vertebrate predators. Pathogens. Feeding inhibitors. Environmental manipulation. Chemical pesticides. Each of these methods has found a place somewhere in the control program for one or more pests. We all know, for example, of the use of the sterile males released against the screwworm, the use of lady beetles against scale insects in California, the use of Bacillzu thuringiensis against cabbage loopers, and so on. Unfortunately, each individual instance of success depends on a special set of circumstances that may be difficult or im- possible to duplicate or approximate with some other species. This fact is often very difficult to get across to the public, who see this or that "new" technique as a breakthrough on old fronts. The sterile male technique, for example-or the use of specific pathogens and parasites-to be really workable may require that there be a practical way either to rear or to trap the insects in large numbers and to maintain continuous rearing or access to large natural populations. These procedures must be worked out separately for each species. They may include the development of artificial foods and extensive and expensive greenhouse and insectary facilities manned by many persons with special training and duties. Watchful Waiting The economic factor is an important one, and one that in for- est entomology problems is especially difficult to assess. The question "Is it worth the expense?" usually comes up even- tually; and then we get into the realm of opinions and emotions and long-range effect, which makes it virtually impossible to give satisfactory answers-at least not without extensive applied research. Even with proven, if limited, success for a given con- trol in a specific instance such as sterile males against screw- worm or fruit fly, or virus against sawflies, or milky disease against Japanese beetle, we are on the defensive with every would-be control agency, whether it is a commercial applicator, a property owner, a garden club, or a public agency, unless, after we have said he can't or shouldn't spray, we can tell him something else to do that is really practical: where to get it, how to use it, or who can do it, and what to expect