« PreviousContinue »
4. A greatly improved virus formulation was developed by utilizing COAX®, a feeding stimulant, boric acid and Eusolex®, a sunscreen to prevent inactivation of the virus. One acre equivalent of the formulation costs about $4.00.
5. A new method of synthesizing the sex attractant at a relatively low cost was evaluated and appears to be feasible.
6. Field populations were suppressed by using the sex attractants to disrupt communication between males and females. This method is effective against low level populations only. Similar studies were made in which populations were first suppressed with diflubenzuron, or with a new formulation of Bacillus thuringiensis. One sex attractant formulation gave suppression for more than one year.
7. The exotic predator Dinorhynchus dybowskyi was released in large numbers in Maryland, Pennsylvania and Connecticut. Large numbers of the parasite Anastatus disperis were shipped to states where this egg parasite is not yet established.
MAJOR INSECT PROBLEMS
Mr. WHITTEN. Some of the members of this Committee will recall an incident involving the Atomic Energy Commission some years ago. They had a $5 million a year project for basic research, just research for the sake of research. I read what this project covered. It was just finding answers for answers' sake on the grounds that somebody might be interested and might want to know. I asked them what they hoped to accomplish since the project was going on for five years. They said they hoped it would be $25 million a year by the end of five years. That was the answer given.
I am trying to find out what we are getting for our research money and how we can go about helping direct it to the areas of greatest need.
If Forest Service is doing all the work, why should we give you the money? And vice versa? I would like you to put into the record a detailed report on what progress you are making and what this Committee might do to see that the old problems get attention.
I am sure you can go out and find new problems, but the old ones are destroying the country. We need emphasis on them.
The Japanese beetle does not seem to be bothering us at the moment. We think we have answers on the khapra beetle and the Mediterranean fruit fly, although we still have outbreaks every once in a while.
So, I wish you would give us a summary of these major problems and let us know what more can be done about them.
Dr. BERTRAND. We certainly will do that and respond specifically on these insects.
Mr. WHITTEN. You might add others. We have to justify the fact that you are getting an increase and everyone else is being cut. To get by with that we have to show that your work is worthwhile. We cannot simply say programs are carried out by the Forest Service. If you get the money, you have the responsibility.
Without objection, the information will be placed in the record at this point.
[The information follows:)
Insect Pests and Diseases in Agricultural Commodities
Insects and diseases cause crop and livestock losses of well over $40 billion. Many of them have major impacts on the environment. Brief accounts of some of these major pests follow. It is also noteworthy that a number of pests which were previously very destructive have become less of a threat because research has developed effective means of control. Some outstanding examples include the Hessian fly on wheat east of the Mississippi which is controlled with resistant wheat varieties at a savings to American agriculture of at least $40 million each year; the citrus blackfly which is controlled by introduced parasites thus eliminating the need for $5 million/year control costs; the cereal leaf beetle and alfalfa weevil which are controlled largely by introduced parasites; the wheat stem sawfly which no longer causes problems because of resistant wheat varieties, and the pea aphid, the spotted aphid, and the blue aphid on alfalfa which are now controlled by resistant varieties. Additionally, the destructive potential of many other major pest insects such as the European corn borer and the boll weevil have been reduced through the application of modern, effective pest management technologies. On the other hand serious reversals have been suffered in dealing with pests such as soil insects and the gypsy moth.
The ravages of the gypsy moth, a tree defoliator, appear to be progressively increasing every few years. In 1980, 5.1 million acres of forest were defoliated. This is an all time high. The pest was introduced into Massachussets in 1869 and was quarantined with moderate effectiveness for a number of decades. After DDT could no longer be used against the pest in the late 1950's, the pest spread rapidly throughout the northeastern corridor of the United States. There is a serious danger that the gypsy moth will spread down the Appalachian chain and ravage valuable forests in the southern U.S.
In areas where the pest is well established, the Forest Service cooperates with State agencies in providing assistance to reduce defoliation and tree mortality. On the other hand APHIS conducts cooperative programs to eradicate isolated infestations outside of the generally infested area and to retard the artificial and natural spread of the pest from the generally infested area.
Some specialists have estimated annual losses caused by the pest at $50 million. However, in 1975 benefit-cost analyses, which were conducted for current and future programs, resulted in estimates of a much greater magnitude. The annual damage caused by the pest in 1975 was estimated at $268 million and the benefit-cost ratio of research was estimated to be between 29.7 and 61.6. The annual damages without control in the entire area where the gypsy moth infestation has occurred and could potentially occur were estimated to be between $249.7 and $516.8 million. Oak mortality associated with recent outbreaks varied from 5 to 80 percent. In addition to timber losses, residential property values are reduced, outdoor recreation is impaired, and damage to wildlife and watersheds occurs.
Research has resulted in (1) establishment of 12 species of predators and parasites, (2) registration of several effective insecticides, (3) registration of a virus and of Bacillus thuringiensis both of which provide biological control, (4) identification, synthesis and use of the gypsy moth sex attractant to detect, delimit and suppress populations, (5) guidelines for assessing socioeconomic impact caused by the gypsy moth, (6) procedures for risk-rating forest stand susceptibility to defoliation, and (7) mass rearing capability to produce both the virus and sterile moths.
A USDA Gypsy Moth Steering Committee outlined the following research approaches which are being followed in gypsy moth research: enhance the effectiveness of established natural enemies, (2) improve the effectiveness of microbial pesticides, (3) further develop use patterns for the sex attractant, (4) further develop the sterile male technique, (5) further develop silvicultural practices for reducing losses, (6) develop an understanding of aspects of population ecology needed to improve the use of control technology, and (7) develop combination treatments of various methods of suppressing the pest.
The khapra beetle is one of the most threatening foreign pests of stored grains and other commodities. Its establishment in the U.S. would cause millions of dollars of losses as well as disrupt domestic marketing and exports of U.S. products.
In 1966 after a decade of costly effort it was eradicated from the four southwestern states and from Mexico. This required the fumigation of nearly 800 buildings and extensive visual inspection of warehouses, transport vehicles, etc., for signs of larvae and cast skins.
During the past year the khapra beetle has again penetrated U.S. quarantines. It has been discovered in buildings in New Jersey, New York, Pennsylvania, and Maryland
SEA/AR scientists and cooperators at the University of Wisconsin and Syracuse University have developed new sensitive techniques for detecting the pest, based on the identification and synthesis of the sex attractant emitted by the adult female. Perhaps more importantly, the scientists have identified several components of wheat germ oil which strongly attract the larvae of the pest.
The wheat germ oil attractants are used in traps which can be placed in locations where the beetles may be present. Male beetles seek females in the traps, but instead are killed by an insecticide. The use of these traps will reduce the costs of inspection and fumigation by providing posititve identification of the presence of the beetles, thus aiding in eradication.
Two additional approaches have been developed. One uses attractant baited traps to disseminate a protozoan disease that rapidly decimates the population. A second approach is to interbreed the pest with a related native species to produce sexually sterile hybrids.
Additional research is needed to (a) find replacements for methyl bromide and other fumigants, (b) obtain sufficient data needed to register the use of the pathogen, (c) conduct practical scale tests with the sterile hybrids, and (d) develop new attractant toxic bait combinations for prophylactic use.
Greenbugs and other cereal aphids
Aphids continue to cause heavy reductions in wheat and barley production. In addition to causing losses by direct feeding, aphids transmit diseases such as barley yellow dwarf which cause serious reductions in wheat and barley yields. One of these aphids, the greenbug, also severely reduces yields of grain sorghum. When injurious aphid populations occur, widespread applications of insecticides are required for control.
Plant resistance in sorghum to aphids represents a real success in reducing losses and in reducing the number of situations calling for pesticide application. Plant resistance has virtually eliminated losses which could have exceeded $200 million from 1976-1980. However, a new strain of greenbug has recently appeared that can attack this "resistant sorghum," SEA/AR researchers have discovered other effective sources of resistance which, it is believed, can combat the new greenbug strain, Research to develop additional resistant varieties is underway but should be increased to counteract other new greenbug strains which are certain to develop. Research will also be initiated to develop management systems to suppress the total aphid populations and prevent their spread throughout the central U.S. as soon as resources permit.
Corn rootworms are serious pests of corn in the mid-west and at a cost of $6.00/acre. More than 20 million acres of corn are treated with insecticides each year to control these pests. In spite of these insecticide applications, root worms cause an estimated $200 million loss in corn production each year on top of the $120 million expended for control.
More effective control methods and management techniques to incorporate into integrated pest management systems have been the recent objectives of our research. Also, SEA/ AR scientists have discovered and identified the sex pheromone of the rootworm, identified and defined many of the ecological factors which cause fluctuations in corn rootworm populations, and have developed methods to increase the effectiveness of insecticides.
Additional resistant corn germplasm is propably available in tropical corns. For climatic reasons, these tropical corns cannot be tested for root worm resistance in the U.S., consequently cooperative research programs are contemplated with corn scientists in Latin America to accelerate the incorporation of resistant germplasm into corn varieties adapted to temperate America.
Information on control and management of corn rootworms is now available to allow the development of pest management systems. Future research should emphasize the practical development of the above control techniques and the development of even more effective pest management systems.
More than 50 species of grasshoppers cause serious losses of rangeland, cultivated forages and crops. Twenty three percent or more of rangeland forage is consumed by grasshoppers each year and heavy populations not only
consume the forage needed for livestock and wildlife, but so overgraze the range that they cause long-lasting ecological damage.
Researchers have developed the use of effective insecticides and are developing biological control agents to be incorporated into grasshopper management systems. Nosema locustae, a grasshopper disease organism, has been registered and research on other pathogens is also underway. New research thrusts will include the development of integrated grasshopper management systems which can be effectively used by private producers and APHIS to keep the number of grasshoppers below economic levels and prevent devastating outbreaks.
The European corn borer and the southwestern corn borer combined cause an estimated $300 million loss in corn production each year. Without corn varieties that are resistant to the first generation of European corn borer these losses would be much greater. Scientists have recently developed germplasm with resistance to both first and second generation of European corn borer and to the southwestern corn borers.
Additional research is needed to further develop resistant germplasm, develop the use of the sex attractants and develop additional chemical and biological control agents.
Mediterranean fruit fly
The Mediterranean fruit fly is potentially one of the most destructive insect pests ever to threaten American agriculture. World-wide it attacks more than 200 different kinds of fruits and vegetables making them unfit to eat. Should this pest become firmly established in the continental United States it could conceivably spread to most of the southern United States.
The cost to American agriculture and to American consumers in case of such spread would be measured in hundreds of millions of dollars annually. These tremendous costs would take several forms: (1) direct losses of marketable production to fruit and vegetable growers; (2) increased cost of production due to cost of control measures; (3) increased cost of transportation and marketing due to mandated commodity treatments, and (4) increased cost to consumers at the market place. Additionally, the U.S. balance of payments could be adversely affected due to the necessity to treat exported commodities. It is conceivable that some foreign markets could be lost entirely if our country's horticultural crops become infested with the Mediterranean fruit fly. Of equal concern is the fact that if we experience a wide geographical spread of this insect, a significant increase in the use of insecticides for control would result. This could lead not only to additional environmental pollution but could also upset the delicate balance of nature that many of our growers of today are depending upon for control of other pests.
Through research we have developed the basic technology necessary to eradicate incipient infestations. This technology consists of highly effective attractants to detect and delimit infestations, a selective toxic bait which does not attract other species, and the sterile male method. Field control