ARS News Service Tip Sheet for April 12, 1997
Agricultural Research Service, USDA
Jim DeQuattro; 301-344-2756; [email protected]
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Biocontrol Duo Gang up on Armyworms
Double trouble may loom ahead for beet armyworms that ravage cotton plants.
Scientists with USDA's Agricultural Research Service are teaming a natural insect virus with a parasitic wasp to put the kibosh on the pest.
The virus, called a nuclear polyhedrosis virus, liquefies the bodies of beet armyworm caterpillars it infects but doesn't harm people, animals or beneficial bugs. The parasitic wasp, Cotesia marginventris, is a native U.S. insect that lays its eggs in the worm. Wasp larvae hatch from the eggs and feed on the pest's innards.
In small field plots, spraying the virus on cotton plants killed over 50 percent of the worms in 4 days. Researchers then released about 500 Cotesia wasps; they doomed half the survivors. In all, the virus-wasp combo killed three-fourths of the beet armyworms.
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Scientific contact: P. Glynn Tillman, USDA-ARS Biological Control and Mass Rearing Unit, Mississippi State, Miss., phone (601) 323-2230, fax (601) 323-0478, e-mail [email protected].
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Snap Beans Fingered as Calcium Source for Youths
Girls and boys absorb two important bone-building minerals--calcium and magnesium--from snap beans as easily as they absorb them from milk, according to an Agricultural Research Service study being reported today at the Experimental Biology 97 meeting in New Orleans.
That's good news to researchers at the ARS Children's Nutrition Research Center in Houston, Tex. They are looking for good sources of calcium to replace the 24-35 percent drop in milk consumption among children and teenagers since the late 1970's. Snap beans are a popular vegetable among
this age group.
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Scientific contacts: Steven Abrams (absorption) or Michael Grusak
(breeding), Children's Nutrition Research Center, Houston, Texas, (713)
798-7000, e-mail [email protected] and [email protected].
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Dieters' Responses Slowed in Study
Women who cut calories to lose weight may inadvertently slow their reaction times, an effect that can continue for weeks after the women have stopped dieting.
That's the finding from a study by scientists with USDA's Agricultural Research Service and the Institute of Food Research of the British Biotechnology Sciences Research Council. The scientists report their findings today (April 9) in New Orleans at a meeting of the Federation of American Societies for Experimental Biology.
Reaction time lengthened by 11 percent in women volunteers who went on a reducing diet directed by researchers from the ARS Western Human Nutrition Research Center in San Francisco. The volunteers' reaction times continued to slow for 3 weeks after they had stopped dieting and started eating
enough to maintain their new, lower weights.
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Scientific contact: Mary J. Kretsch, USDA-ARS Western Human Nutrition
Research Center, San Francisco, Calif., phone (415) 556-6225, e-mail
[email protected].
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Berry Good Food for the Brain
Diets high in antioxidant foods appear to protect the brain against oxidative damage, if rat studies by Agricultural Research Service and University of Denver scientists are any indication. Oxidative damage is thought to lead to age-related dysfunctions such as loss of memory or motor
coordination.
In the studies, rats that ate extracts of strawberries, blueberries or spinach as part of their daily diet fared far better on brain cell function tests than the animals getting chow alone. The fruit and vegetable extracts offered at least as much protection as vitamin E against oxidative damage, an ARS scientist said yesterday at the Experimental Biology 97 meeting in New Orleans.
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Scientific contact: James A. Joseph, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts, Boston, Mass., phone (617) 556-3178, e-mail [email protected].
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Too Little Magnesium Makes One Work Harder
Older people whose heart rate soars and energy dives during aerobic exercise may want to take a closer look at their magnesium intake, according to new Agricultural Research Service findings.
In a study, a group of post-menopausal women experienced a significant drop in their work efficiency when their magnesium intake was reduced to a little more than half of the Recommended Dietary Allowance for three months. That occurred even though blood magnesium levels showed no sign of
deficiency, the study leader reports today at the Experimental Biology 97 meeting in New Orleans.
The study is the first to look at the effect of low magnesium intakes on the physiological function of people over age 55. According to the latest USDA nationwide food consumption survey, fewer than one-third of people over age 50 consume the recommended amount of magnesium through their diet.
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Scientific contact: Henry C. Lukaski, ARS Grand Forks Human Nutrition Research Center, Grand Forks, N. Dak., phone (701) 795-8353, email [email protected].
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* ARS Info on the World Wide Web: http://www.ars.usda.gov/is
* The ARS Information Staff is at 6303 Ivy Lane, 4th Floor, Greenbelt MD
20770, phone (301) 344-2303, fax 344-2311.
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