Adult Psylliodes chalcomerus insect (Image
courtesy Mark Volkovitsh, Zoological Institute, Russian Academy of Sciences.
Not available in 300 dpi)
Larva of Psylliodes
chalcomerus that tunneled into a starthistle stem. (Image courtesy Mark
Volkovitsh, Zoological Institute, Russian Academy of Sciences. Not available in
Flea Beetle Getting at Root of Invasive Weed
Problem By Luis
June 24, 2003
Service scientists are identifying the distinguishing traits of a flea
beetle that researchers overseas believe is a useful enemy of the invasive weed
called yellow starthistle.
Scientists at the Biotechnology and Biological Control
Agency in Rome and the Russian
Academy of Sciences' Zoological Institute in St. Petersburg, working with
the ARS European Biological Control
Laboratory in Montpellier, France, found that the insect, Psylliodes
chalcomerus Illiger, seems to have an appetite for yellow starthistle's
roots, stems and leaves. All previously known insect enemies of the weed attack
However, only a specific population of P. chalcomerus was
found to be effective.
It's vital that the insect's correct identity be verified, not
only to assure that the right insect is used to control the weed, but also to
determine if this beetle might constitute a new, previously unrecognized
species. So the European scientists sent samples of it to insect identification
specialists at the ARS Systematic
Entomology Laboratory in Washington, D.C.
There, entomologist Alexander Konstantinov, a world expert on
this group of beetles, is comparing the specimens with insects in the
National Collection of the Smithsonian Institution, where his lab is
Yellow starthistle, Centaurea solstitialis, probably
costs the nation's livestock and forage crop industries millions of dollars
each year. It supplants valuable grazing areas and is toxic to horses, causing
a fatal illness known as chewing disease.
Accidentally introduced into California during the mid-19th
Century in alfalfa seed shipments, yellow starthistle can now be found in 28
states and most of southern Canada. It also causes economic distress in Chile,
Australia and South Africa. Once established, it is spread mostly through human
Some seeds of the host plants used in the European studies were
obtained from the ARS Western Regional
Research Center's Exotic Invasive Weeds Research Unit in Albany, Calif.
ARS is the chief scientific research agency of the
U.S. Department of Agriculture.