ARS News Service
Agricultural Research Service, USDA
Jim De Quattro, (301) 344-2756, [email protected]
-----------
Ranking Soldier Flies
Telling the good soldier flies from the bad ones just got easier.
Many species of soldier flies are beneficial to agriculture because they
help decompose plant material. But other species are pests of sod and
wheat.
For the first time, scientists with USDA's Agricultural Research Service
have compiled detailed descriptions of 33 genera of the subfamily
Beridinae of the soldier fly family Stratiomyidae. The ARS monograph also
proposes nine new genera, describes two new species and properly
classifies many misplaced species for the first time.
Each of the 33 genera is described in detail and a catalogue of world
species and their geographic distributions is presented. The scientists
present a hypothesis on the evolutionary relationships between genera and
the placement of the subfamily with respect to other groups of flies.
The monograph will be useful to scientists studying these flies and also
will aid agents at U.S. ports of entry who monitor immigrant species that
may be potential pests.
Scientific contact: Norman E. Woodley, USDA-ARS Systematic Entomology
Laboratory, Museum of Natural History, Washington, D.C., phone (202)
382-1802, [email protected].
----------
How Chemicals Seep into the Aquifer
Scientists have answered one of the questions of the Midwest: how drinking
water coming from aquifers gets contaminated with chemicals.
Walnut Creek, a tributary of the South Skunk River near Ames, Iowa, is a
typical small stream in the area. Before flowing into the river, the
creek passes over a sand and gravel aquifer.
Scientists with USDA's Agricultural Research Service have confirmed the
movement of water through the creek bed and into the underlying aquifer.
They accomplish this by measuring water levels in the aquifer and flow in
the stream on two sampling dates. Chemical analyses of 24 water samples
showed that the water entering the aquifer contained nitrate and
herbicides, including atrazine.
The scientists estimate that the creek could contribute substantially more
atrazine to the aquifer than leaching through a field equal in area to
that of the streambed.
Both the stream and aquifer conditions studied are common in the Corn
Belt. Alluvial aquifers, sometimes called "buried valley aquifers," are
found near most major rivers in the region.
This type of aquifer has been found to contain the greatest contamination
of all ground water resources in the Corn Belt. Defining the
stream-aquifer connection could prove critical in explaining
contamination of important ground water resources used by communities and
farmers. Implications are that managing fields upstream may be more
important than managing fields over an aquifer.
Scientific contact: Michael R. Burkart, USDA-ARS National Soil Tilth
Laboratory, Ames, Iowa, phone (515) 294-5809, fax (515) 294-8125,
[email protected]
----------
Hairy Vetch Mulch System Moves to Poland
Hairy vetch is being auditioned in Poland as a natural mulch for growing
vegetables--a system developed by a plant physiologist with USDA's
Agricultural Research Service.
In collaboration with the ARS scientist, a researcher at the Entomology and
Plant Protection Techniques Laboratory at Skierniewicie (pronounced
"scare-na-vich-ee"), Poland, is evaluating hairy vetch and other cover
crops for adaptability to Poland's chilly climate. The scientists also
want to find out whether the natural-mulch system can help overcome other
problems faced by Polish farmers, such as limited rainfall and
contamination of surface and groundwater by chemical fertilizers, manures
and pesticides.
Scientific contacts: Aref A. Abdul-Baki, ARS Vegetable Laboratory,
Beltsville, Md., phone (301) 504-5057, fax (301) 504-5555, e-mail
[email protected]. Stanislaw Kotlinski, Entomology and Plant
Protection Techniques Laboratory, Skierniewicie, Poland, phone
48-46-33-2947, e-mail [email protected].
----------
Piglets, Pituitaries and Chilly Temperatures
Some like it hot--especially newborn pigs, whose health, well-being and
survival are threatened when temperatures dip. Scientists with USDA's
Agricultural Research Service say new information about piglets' ability to
cope with cold stress can help producers get little porkers off to a good
start.
Piglet survival and growth are the keystones of pork profitability.
Currently, 12 to 15 percent of piglets die before they are weaned. It's
been calculated that saving one piglet per litter born in the United States
is worth $350 million annually.
ARS scientists were the first to study the effects of temperature on baby
pigs' pituitary gland. Located underneath the pig's brain, this gland
secretes hormones that control important biological responses to stress and
can indicate whether the piglet is experiencing stress.
Scientific contact: Robert L. Matteri, ARS Animal Physiology Research,
University of Missouri, Columbia, Mo., phone (573) 882-1047, e-mail
[email protected].
----------
Research Counterattack Against New Sorghum Fungus
Sorghum ergot (UR-get), an emerging fungus disease, faces more scrutiny at
the Agricultural Research Service. ARS has released $100,000 in funds to
expand research against the disease, found this year in Puerto Rico and
Texas.
Grain sorghum is the nation's number two feed grain. Sorghum ergot mainly
threatens hybrid sorghum seed crops. Texas is the world's major supplier of
hybrid sorghum seed, and U.S. sorghum winter-nursery programs are
concentrated in Puerto Rico. First found in the western hemisphere in 1995,
sorghum ergot raced through South and Central America and the Caribbean.
Scientists found it in Puerto Rico in February and Texas in March.
To combat the ergot, ARS will expand research at its Tropical Crops and
Germplasm Research Laboratory, Mayaguez, P.R., and its Foreign Disease-Weed
Research Laboratory, Frederick, Md. The research will be conducted in
cooperation with Texas A&M University. The scientists will:
* Continue evaluating fungicide treatments that were tested by ARS
scientists in Puerto Rico to kill ergot spores contaminating seed of
breeding lines shipped to North America.
* Identify resistant plants from ARS' germplasm collection. Resistant
varieties would give growers long-term protection.
* Test a fungicide to suppress ergot infections on sorghum plants. Texas
A&M University plans tests on commercial seed farms in south Texas and
Mexico.
* Confirm the ergot's identity. Principal sorghum ergot species are
Claviceps sorghi from India and C. africana, of African origin, the species
found so far in the western hemisphere. Evidence to date shows C. africana
makes no toxins, unlike a different ergot species, C. purpurea.
ARS scientists in Puerto Rico operate a World Wide Web site as an ergot
resource for scientists, industry and growers. The site, which includes
photos of ergot on plants, is at:
http://www.ars-grin.gov/ars/SoAtlantic/Mayaguez/sorghum.html
----------
Scientific contacts: Morris Bonde, ARS Foreign Disease-Weed Research
Laboratory, Frederick, Md., phone (301) 619-2860, fax 619-2880,
[email protected]; Jeff Dahlberg, ARS Tropical Crops and
Germplasm Research Laboratory, Mayaguez, P.R., phone (787) 831-3435, fax
831-3386, [email protected]; Richard Frederiksen, Texas A&M
University, College Station, Texas, phone (409) 845-1227, fax 845-6483,
[email protected]; Gary Odvody, Texas A&M Research and Extension
Center, Corpus Christi, Texas, phone (512) 265-9205, fax 265-9434,
[email protected].
RSS