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Although a number of these advances are in practical use, there is a need for improved methods of using pheromones for mating disruption, for methods of producing more competitive sterile insects, and for additional plant growth regulators. In addition, more information is needed on the genetics, physiology, and behavior of the pink bollworm. Improved population models, including studies of migration are also needed to design improved programs. The influence of pink bollworm populations in Mexico on those in the U.S. needs to be determined.
Southern Pine Beetle The Southern spine beetle (sPB) is the most destructive of the eastern species of bark beetles and occurs throughout the Southeastern and Southern States. It causes significant pine mortality every year somewhere in the South. Outbreaks have been reported as far back as the 1750's. About 800,000 thousand cubic feet (MCF) of pine timber has been killed since 1968; an annual loss averaging about 72,500 MCF. Since 1974, populations of the southern pine beetle have declined to a low in 1978 when about 7,800 MCF of pine timber were killed. Now on the rise again, about 125,200 MCF of timber is estimated to have been killed in 1979, equivalent to the lumber needed to build about 55,000 average-size houses. The losses in 1980 were also high and were particularly severe in Mississippi, Alabama, Georgia, and South and North Carolina.
Such losses upset management plans, reduce potential yields from managed stands, and devastate the forest holdings of small, private nonindustrial land owners- the principal owners of commercial forest land in the South. In years of peak SPB damage, a glut of beetle-killed timber is created that exceeds the processing capacity of local mills.
Major accomplishments from the Expanded Southern Pine Beetle Research and application program (ESPBRAP) were as follows; (1) Stand risk-rating systems developed to determine susceptibility to beetle attack. It allows foresters to identify stands that need special attention when beetle populations increase and to set priorities for silvicultural treatments (2) Sawmill operator's guide prepared to show possibilities for profit in limber from SPB killed trees. (3) Damage prediction model developd to estimate future tree mortality over large areas. Effects on other forest resources can also be estimated. (4) A stand-growth model for plantations allows simulation of the effects of management practices on tree growth. (5) Dursban 4E insecticide approved by EPA for bark beetle control (6) Methods for sampling SPB populations developed and tested. (7) Spotgrowth model to predict tree mortality in "spots" over large areas developed and being tested. (8) Aerial survey and navigation systems developed to estimate size and number of infestations and volume of dead trees over large areas. (9) Progress toward use of behavioral chemicals (pheromones or sex attractants) to disrupt normal attack behavior of SPB.
A current research program is underway with emphasis on the following problems: (1) The combined effects of the SPB insect natural enemies (parasites and predators) and associated mite and nematode complex on SPB population trends. (2) The role of symbiotic microorganisms associated with SPB in reproduction and development. (3) Biological and physiological characteristics of stressed pine trees that render them attractive and susceptible to SPB attack and survival. (4) Evaluate existing hazard-rating systems and silvicultural treatments developed for reducing losses from SPB. (5) interrelationships amoung SPB populations, natural enemies, associated microbes, and individual tree and stand characteristics (population dynamics). (6) Evaluate candidate chemical insecticides for protection of individual trees from SPB attack. (7) Effects of insecticides on SPB parasites and predators. (8) Effects of insecticides on soil and aquatic organisms.
Major research studies on Southern Pine Beetle with priority for early attention are: (1) pilot test of models for estimating impacts and spot growth of SPB infestations. (2) Develop methods for measuring the cost and benefits or cost effectiveness of selected treatment tactics applied under forest conditions. (3) Test and refine the sawmill decision model in two geographic locations. (4) Simplify field and office procedures for estimating SPB populations in trees, spots, and areas. (5) Develop models for describing and predicting host susceptibility to SPB attack. (6) Pilot test SPB stand-rating systems in several geographic locations in the southeast. (7) Develop and test formulations of pheromones for supression. (8) Integrate findings for ESPBRAP into SPB management systems.
Much new technology has been developed by the program is now in need of validation, pilot testing, and transfer to users. General areas of need are to validate and refine pest management decision making processes and to further analyze and synthesize the large amount of knowledge on SPB to properly design integrated SPB management and treatment strategies.
Specifically, future needs & major knowledge gaps to be filled are:
Cooperative Research and its cooperators in the State agricultural experiment stations and forestry schools have participated in an expanded southern pine beetle program since 1975. SEA/Cooperative Research received $844,532 in fiscal year 1980 from the forest service and $1,080,000 in fiscal year 1981 for use in the jointly planned Forest Pest Research and Development Program on Southern Pine Bark Beetle and the Canada/U.S.A. Spruce Budworms Research, Development and Application Program. In Fiscal Year 1981, $633,000 is available from the Forest Service for research and development on Southern Pine Bark Beetles.
Research by the State agricultural experiment stations and forestry schools in Georgia, New Hampshire, North Carolina, Texas, and Virginia contributed to developing techniques for evaluating the impact of southern pine beetle populations; insect sampling and population dynamics; mortality and competition factors; soil, tree, stand and climatic characteristics; development of behavioral chemicals; evaluation of toxicants; and stand manipulative practices. This information has been provided to forest managers. Currently the State agricultural experiment station and forestry school researchers are contributing in the areas of characterizing flight dispersal by the Southern Pine Beetle, dynamics of endemic Southern Pine Beetle populations, development of a pheromone system, deve lopment of sampling procedures and statistical models and decision-support system development for Southern Pine Beetle Management,
Douglas-Fir Tussock Moth The Douglas-Fir Tussock Moth (DFTM) is a de foliator of major importance in the interior Douglas fir and true fir forests of western North America. Occasionally, its populations increase catastrophically, causing extensive mortality, top- kill, and growth loss in trees of all ages within various parts of its range. The deleterious effects of the moth have been severe from the interior of British Columbia to Mexico, and from the Rocky Mountains to the Cascade and Siskiyou Ranges of Washington, Oregon, and California. Damage inflicted by the DFTM can adversely affect local forest operations and regional forest management objectives.
The last major outbreak of DFTM occured from 1971-1974 in Oregon, Washington, and northern Idaho in which timber and growth losses reached 200,000 thousand cubic feet (MCF), creating major problems in salvage and forest regeneration. The insect has remained at low levels since the 1971-1974 outbreak collapsed. Major outbreaks tend to occur every 8-10 years which suggests that the next outbreak can be expected in the early 1980's.
The Expanded Tussock Moth Research Program was successful and major research accomplishments have resulted in (1) Increased understanding of biology, nutritional requirements, and genetic variation among populations of DFTM. (2) Increased understanding of DFTM population ecology, including the role of natural enemies in the decline of outbreaks and in maintaining low-density populations. (3) A stand outbreak model was produced that predicts tree mortality, top-kill, and growth reduction.
(4) A stand prognosis model was developed which projects long-range stand development, with and without DFTM outbreaks. (5) A model was developed that projects socioeconomic impacts on timber, water, wildlife, and fire hazard. (6) Sampling methods have been developed for eggs, larvae, and adults. (7) The insect's geographic range has been defined more accurately by pheromone (sex attractant) trapping of adult males. (8) One chemical insecticide was registered for aerial suppression of DF IM, R&D was completed on two others. Several are now registered for ground application. (9) Two microbial insecticides were registered for DFTM: Bacillus thuringiensis and a nuclear polyhedrosis virus (NPV). The DFM NPV is the first virus to be registered against a forest insect in the United states. (10) Improvements in aerial application technology were made., eg., an instrument was designed that provides continuous information or air-speed temperature, hummidity, spray pressure and flow rate; three models were developed to simulate spray behavior. (11) A preliminary pest management system has been modeled which describes the likely conequences of each of many decision alternatives for supression of tussock moth outbreaks.
Additional research is needed in the following areas: (1) relationship of tree nost physiology and resistance to DFTM; (2) physiology of insect-host interactions; (3) genetic variability among DFTM populations; (4) relation between local stand and site conditions and outbreaks; (5) natural enemy complex and its affect on both sparse and dense DFTM populations; (6) long-range biological effects of outbreaks, for example, on big game habitat, birds, water flow and runoff; (7) refine sampling and population evaluation methods: (8) conduct additional field experiments with chemical insecticides to refine dosage levels and application strategies; (9) feasibility of using pheromone (sex attractant) for preventive treatment of suboutbreak DFTM populations; (10) test NPV against release phase or incipient phase of DFTM outbreaks and determine carryover effects in the year following application; (11) validate projections of all model components during preoutbreak and outbreak periods; (12) adapt models for use region by region; (13) validate all components of the pest management system.
A continuing research program is underway with emphasis on the following problems: (1) importance of natural enemies and diseases in causing increases and decreases in DFTM populations through silvicultural practices; (2) strategies for reducing DFTM populations through silvicultural practices; (3) long-term effects of de foliation by DFTM on tree and stand growth; (4) improve detection and evaluation survey techniques using pheromones, including a trapping system to predict critical population changes; (5) feasibility of controlling DFTM by the mating disruption technique using pheromones; (6) improved microbial spray formulations of Bacillus thuringiensis NPV; (7) evaluation of new candidate insecticides for suppression of DFTM.
The major animal diseases and pests of importance to the U.S. livestock producers can be divided into four broad areas. These are the foreign animal diseases which are a threat to U.S. livestock; zoonotic diseases which affect man and are of public health significance; production diseases such as mastitis, shipping fever, and enteric diseases which currently reduce livestock production efficiency; and insect pests which also reduce livestock production efficiency or transmit disease. These diseases and insect pests of livestock severely decrease or severely limit production of high quality animal proteins in the United States and throughout the world. Currently, it is estimated that 15 to 20 percent of food animals die before reaching market. Death losses, growth inefficiencies, vaccination costs, and disease treatment in livestock cost the U.S. consumer an estimated $12 billion annually. Internationally the effect of livestock diseases on the economics and the human nutritional levels are even more significant. In the future these losses and inefficiencies in livestock production will be of even greater importance as agricultural land and energy resources become limited and the world population continues to expand.
Foreign animal diseases
The foreign animal diseases indirectly impact on the United States economy by restricting the international movement of animals and animal products; however, their major significance is the potential devastation of our livestock industry in the event of accidental introduction. Foot-and-mouth disease, FMD, is still a major disease of the cloven-hoofed animals - animals vital for the production of food and clothing in many parts of the world. Mortality due to foot-and-mouth disease is usually low; however, diseased animals may lose up to 20 percent of their body weight and stop lactating, resulting in major economic losses in animal production. A recent study simulating a foot-and-mouth disease outbreak throughout the United States showed that if not controlled, a foot-and-mouth disease outbreak would result in direct and indirect costs of over $10 billion the first year. The SEA-AR research has concentrated on pathogenesis, improved diagnostic tests, improved disinfectants and vaccine development. Research is needed to characterize the immune response following infection and vaccination and to develop an effective subunit vaccine for use in endemic areas.
African swine fever
African swine fever has probably existed as a non-fatal infection of indigenous wild swine in Africa for centuries. The disease was always highly fatal to domestic swine, and control was accomplished by slaughter and disposal of all infected herds. However, in Angola free ranging of domestic swine was permitted and over a period of years the African swine fever virus became endemic in the domestic pig population. It was soon recognized that evolutionary modification of the virus had occurred, allowing a large percentage of surviving domestic pigs to serve as virus carriers. In 1957, African swine fever spread to Portugal and later to other southern European countries. A new form of African swine fever thus emerged which was less lethal than classical African swine fever, and subacute and chronic cases are more commonly seen.