Two "New" Moths May Thwart Troublesome
Weeds
By Luis
Pons February 20, 2007
Two recently discovered moth species show promise for helping keep a
pair of emerging invasive weeds in check.
One of the small moths Agricultural Research Service (ARS) entomologist
John W.
Brown helped finda new species of Dichroramphais seen as
a possible biological control agent for Chromolaena odorata, a plant
known as Siam weed, among other names. It ranks among the world's worst
invasive weeds.
Originally from Central and South America, C. odorata is now
found in Southeast Asia, Africa and many Pacific islands, where it impacts land
used for forestry, pasture and crops such as rubber, coffee, coconut, cocoa and
cashew.
Brown, who is with the ARS Systematic Entomology Laboratory (SEL)
in Washington, D.C., worked with Costas Zachariades, an entomologist with South
Africa's Agricultural Research Council
's Plant Protection Research
Institute, to identify and characterize the new Dichrorampha
species.
The other moth Brown helped discoverCochylis
campulocliniumattacks Campuloclinium macrocephalum, a plant
commonly known as pompom weed that's become particularly troublesome in South
Africa. Originally from Central America, pompom weed displaces native pasture
vegetation in grasslands and wetlands.
According to Brown, the two findings are potentially important because
caterpillars of many species of small moths serve as excellent biological
control agents for invasive weeds. By feeding on weeds' flowers or other
reproductive parts, they provide an alternative to herbicides and costly
mechanical removal.
Each year, SEL scientists in Beltsville, Md., and Washington, D.C.,
identify and classify more than 60,000 specimens of insects and mites that can
impact U.S. agriculture and security. Many of these samples are sent from
outside the United States.
Specimens of the new Dichrorampha specieswhich was first
described and illustrated from Jamaicawere sent to SEL by Zachariades.
C. campuloclinium was first described from Argentinean samples.
A litmus test for measuring both moths as biological control agents
will be the extent of the exclusivity with which they feed on their intended
targets, according to Brown.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.