more information on curbing the pests in Agricultural Research. .
Orchid Pest Targeted in Hawaii
By Marcia Wood
September 19, 2000
Small snails that feast on roots of exotic Hawaiian orchids are the focus of
new studies by Agricultural Research
Service scientists in Hilo, Hawaii. The tiny mollusks, known to scientists
as Zonitoides arboreus, are hard to detect and even harder to kill with
commercial chemicals, according to ARS biologist Robert G. Hollingsworth.
Also called bush or orchid snails, they have bluish-grey bodies protected by
yellow-brown, translucent shells. Their coloration, plus their small size (a
full-grown adult is smaller than a fingernail), make the snails hard to find.
In addition, they live and work independently, so they are harder to see than
if they stayed in groups.
In a survey, Hollingsworth and colleague Kelvin T. Sewake of the
University of Hawaii found that about half
of the growers that they queried in Hawaii complained that Z.
arboreus costs them, on average, about $5,000 a year in control expenses
and lost sales. Even if only two or three snails are feeding on an orchid in a
4-inch pot, the marauding mollusks can eat up all of the surface roots in only
a couple of months.
To combat the pest, Hollingsworth is trying to learn more about its biology.
And he's working to build a large colony of wild snails for his tests of
molluscicides that can be used to kill the snails without harming the orchids.
An article in the September 2000 issue of ARS Agricultural Research magazine
Horticultural research is a key part of ARS mission. For more
information on ARS programs that impact horticulture see the list of "Crop
Production, Product Value and Safety" national programs at:
ARS is the USDAs chief research
Scientific contact: Robert G. Hollingsworth, ARS
U.S. Pacific Basin Agricultural Research
Center, Hilo, Hawaii; phone (808) 959-4349, fax (808) 959-4323,