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SELECTED EXAMPLES OF THE SUCCESSFUL BIOLOGICAL CONTROL OF INSECT AND WEED PESTS IN THE U.S.a/

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a/ Control exerted by biotic agents is effective and substantial in at least part of the geographic distribution of the pest species, if not throughout the range of the pest.

Mr. WHITTEN. You also state that not one documented example of the use of biological control as a component in an integrated nematode management system exists. Are you referring just to the U.S. or is this worldwide, and why do you feel this is true?

Dr. BERTRAND. This appears to be true on a worldwide basis with the possible exception of research within the U.S.S.R. A paper presented at a recent International Congress indicated that work of this nature may be in progress within the Soviet Union. It is felt that emphasis by the U.S.S.R. on the integrated pest management approach is ahead of the rest of the world. The reason nematodes are not controlled biologically is because effective chemicals-nematocides are available that provide adequate control. This, plus the lack of visibility of these organisms within the soil, has resulted in little public interest and a very limited interest on the part of the scientific community. With the recent withdrawal of several chemical nematocides from the market, there has been more interest in the utilization of biotic agents such as fungi and other nematodes for biological control purposes. It should be noted that there has been considerable effort to develop nematode-resistant varieties of plants as part of the overall ongoing control technology.

ALFOMBRILLA

Mr. WHITTEN. You are requesting an increase of $1,200,000 for research in support of APHIS plant and pest control programs. One of the problems you refer to is that of a poisonous weed called alfombrilla. What exactly is this weed, where in the world is it grown, and what would happen to the U.S. cattle industry if it got into the U.S.?

Dr. BERTRAND. Alfombrilla is a small perennial weed about 10 inches tall which is highly poisonous to animals. It is native to north central Mexico. Cattle, sheep, and goats are killed by alfombrilla when they eat as little as 6 ounces per day for three days. Alfombrilla is a devastating poisonous plant to cattle in the Mexican State of Chihuahua. It is spreading north there and is now immediately south of the U.S.-Mexico border. The U.S. cattle industry would be devastated by this poisonous weed if it enters the U.S. and becomes widely distributed on western U.S. rangelands.

APHIS MEDFLY PROGRAM

Mr. WHITTEN. In this same area of research you make the statement that additional funds will be used to improve mass production and release of sexually sterile Mediterranean fruit flies. The Medfly rearing program is an APHIS program. How do you work in support of this program, and how do you plan to use your resources in this area?

Dr. BERTRAND. The Animal and Plant Health Inspection Service together with its several cooperators is engaged in a battle against the Mediterranean fruit fly on two fronts; one in Mexico and Central America and one in the State of California. Among the tools used to combat this insect is the rearing and release of massive numbers of sterilized insects with the objective of overwhelming and eradicating the pest population. It is the responsibility of the Science and Education Administration to provide,

through research, the very best technology available relative to the rearing and release of sterile flies. Our resources will be dedicated to the establishment of protocols for efficient and dependable mass production and use of sterile Mediterranean fruit flies. Research efforts will be concentrated in the areas of automated rearing technology, definition and testing of diets, efficient sexing procedures, safe handling and shipping techniques, minimum effective sterilizing methods, and effective field release systems.

DETECTION OF AGRICULTURAL CONTRABAND

Mr. WHITTEN. You are requesting an increase of $3,290,000 for plant protection and quarantine research in support of APHIS/ FSQS/FDA programs. Part of these funds will be used to continue work on the development of sensitive instrumentation to detect agricultural contraband in passengers' luggage entering the United States. What type of instrumentation do you hope to develop? Dr. BERTRAND. Currently our research is directed to studying the feasibility of three different types of instrumentation. The most promising at this time are detectors that sense aromas and other volatile materials that typically emanate from each of the many types of contraband plant and animal materials. We are currently cataloging these materials and studying potential detectors that will adequately discriminate between these and other materials commonly carried in luggage such as toiletry and perfumes.

The most sensitive and most discriminating instrumentation for detection of odors is based upon a multiple mass spectrometer, but currently available instruments are not rugged and are expensive. We hope to use the principles of mass spectrometry to adapt a device which is small, rugged, and usable by non-scientists and reasonably priced.

Another device which is somewhat less discriminating and sensitive than mass spectrometry, but potentially very useful, is based upon infrared absorbance spectrometry. It uses the Fourier-transform technique which makes it rapid and sensitive. It can be used to detect the volatile components, associated with odors, from foodstuffs. The device could be readily miniaturized and computer operated. It could be priced much less than a mass spectrometer, is rugged and easy to operate.

Another device which might be used is based upon the piezoelectric effect. Piezoelectric or pressure sensitive crystals with inherent frequencies such as the quartz crystal in a watch can have their frequencies modified if chemicals are absorbed on their surfaces. We can easily observe the change in frequency. Devices based on this principle could be used to detect volatile components of food. Although such devices are cheap, they currently lack sensitivity, discriminating power, and take considerable time to recover.

Other detection methods being investigated employ X-ray and microwave energy. These methods yield images which are learning to resolve automatically into images.

Mr. WHITTEN. What successes have you had in this area to date? Give us some examples, please.

Dr. BERTRAND. We hope to have the feasibility phase of the study completed by the end of this fiscal year and plan to move directly to development of the instrumentation system.

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