Low-Dose Pesticide Stops Termites
Estimates are that damage from Formosan subterranean termites alone
costs U.S. consumers about $1 billion annually in control and repair
costs. So researchers are hoping that the patenting of a tasty new toxic
bait with termite appeal will bring closer to reality another potential
solution to widespread termite problems. This new termiticide relies
on low concentrations of naphthalenic compounds similar to those used
in mothballs. Tests have shown that even at low doses, the new bait
is also effective against native Eastern subterranean termites.
In collaborative research with the USDA Forest Service, researchers found that not only do certain naphthalenic compounds work against termites, they also prevent wood decay. So they could one day replace heavy metals such as arsenic, chromium, and copper currently used as wood preservatives. But when combined in a cellulose-based matrix, they form a slow-acting toxic bait that termites take back to their colonies. Effective even at low doses, these baits would be both economical and environmentally friendly.
Another new database is now available, free and online, to help ensure
inclusion of adequate levels of the nutrient choline in daily diets.
Among other functions, choline helps the body absorb and use fats, including
those that become part of cell membranes. Choline also helps the body
use acetylcholine, a neurotransmitter that sends signals across nerve
endings. The adequate daily intake is set at 425 mg for women and 550
mg for men. Top sources of choline include meat, nuts, and eggswith
just one large, hard-boiled egg providing 112 mg, one-quarter of a woman's
Just 2 years ago, scant analytical data existed on the choline content of foods. This new specialty database is the result of a cooperative project with University of North Carolina-Chapel Hill researchers, who analyzed the foods included in the compilation. The database will especially help those who need to minimize their choline intake. Access it at www.nal.usda.gov/fnic/foodcomp.
About a million dairy goats are being raised today in the United States
for milk and cheese production. The high protein and low cholesterol
levels in their milkplus its agreeability to many consumers who
are unable to drink cow's milkare steadily increasing its popularity.
But producers need to be constantly on the lookout for infection of
their animals by Brucella melitensis. This bacterium causes a
disease called brucellosis in sheep and goats. In people, B. melitensis
infection causes Malta fever, characterized by fever and headaches.
While few cases of brucellosis have occurred in U.S. livestock since
1972, it's essential that producers maintain vigilance to ensure that
it doesn't somehow infect their herds. B. melitensis is particularly
common in Latin America, central and southwest Asia, and the Mediterranean
Now a test for detecting B. melitensis in bulk goat's milk has been developed by modifying an ELISA (enzyme-linked immunosorbent assay) test originally developed in 1984 to check cattle for B. abortus.
In ongoing efforts to find economical and profitable end uses for the
corn fiber and distiller's dry grains with solubles (DDGS) left over
from making ethanol, scientists have modified the fungus Fusarium
sporotrichioides. They've given it genes for making lycopene and
other carotenoids. This might one day lead to mass-production of lycopene
from ethanol coproducts, rather than by extracting and purifying it
Regular consumption of lycopene appears helpful in preventing some
cancers. While tomatoes and watermelon are good food sources, some consumers
rely on dietary supplements for their lycopene.
Corn fiber would be an ideal raw material for fungal lycopene production because it's abundant and costs about a nickel a pound. With around 4 million tons of the fiber to dispose of annually, distillers usually sell it inexpensively, as livestock feed. When cultured in the laboratory, the modified fungus can produce 0.5 mg of lycopene per gram of dry weight in 6 days. The next step will be scaling up the process, culturing F. sporotrichioides in fermenters on a growth medium containing corn fiber or DDGS.
"Science Update" was published in the October 2004 issue of Agricultural Research magazine.