The coordinator of the IPM Program at the University of Rhode Island
has become a detective solving the mystery of the lily leaf beetle, a pest
that is devastating lilies within a 30-mile radius of Boston, Massachusetts.
To find a natural enemy of this scarlet and black pest (below), Dick Casagrande
and graduate student Sayles Livingston recently travelled to France. There
the beetle exists but does not reach damaging populations. They found
parasitized
larvae of the lily leaf beetle, collected them, and brought them back to
Rhode Island. In a quarantine laboratory, each larva has produced not lily
beetles, but up to two dozen parasite larvae. Eventually these larvae will
develop into beneficial adults-perhaps wasps-that probably do not exist
in the United States.
As these beneficials are developing, another scientist is in China, where
the lily leaf beetle is believed to have originated. She is studying the
distribution and natural enemies of the beetle.
This type of problem solving is known as classical biological control. If
successful, beneficial insects will replace the insecticides that are currently
protecting lily-of-the-valley, Solomon's seal, Asiatic and Oriental lilies,
and other plants being attacked. Until then, gardeners and landscapers in
the area are being advised to apply neem products and other least-toxic
materials, and to avoid transplanting lilies away from the Boston area.
State IPM Coordinator
Richard A. Casagrande
210 Woodward Hall
Plant Sciences Department
University of Rhode Island
Kingston, RI 02881
401-874 2924
return to IPM in the Northeast Region 1996 Report, Table
of Contents