Disease-Carrying Ticks in for TroubleBy
It's unclear how this El Niño winter will affect 1998 tick
populations. But chemist Patricia Allen of USDA's
Agricultural Research Service is ready
and waiting nonetheless.
Since early 1997, she's been exposing black-legged deer ticks to spores of
naturally occurring fungi at ARS'
Parasite Biology and
Epidemiology Laboratory in Beltsville, Maryland. Of the half- dozen fungi
she has tested under controlled lab conditions, Metarhizium anisopliae
proved the most lethal to the ticks, especially against juvenile forms.
Now she's hoping to show that the fungus will also kill ticks under natural
conditions. Of special interest is the impact on tick eggs and emerging larvae.
To that end, she'll begin a first round of outdoor tests in late April on
small-scale plots at Beltsville. She'll spray a commercial preparation of M.
anisopliae developed by Ecoscience Corp. of East Brunswick, New Jersey.
Allen's research is part of a project to explore the potential and safety of
using beneficial fungi and nematodes as non-chemical tick controls. Her approach
targets black-legged deer ticks because the pests spread the bacterium
responsible for Lyme disease in humans. In 1996, the federal
Centers for Disease Control and Prevention in
Atlanta, Ga., received more than 16,000 reports of Lyme disease.
With this winter's wet, mild weather, Allen and ARS colleague John Carroll
report little trouble collecting enough ticks for their studies at the
Beltsville lab. Carroll, an entomologist, coordinates Maryland's participation
in the ARS-led Northeast Regional Tick Control Project. This multi-state project
uses special feeding bins to lure deer into being coated with a chemical called
amitraz. The chemical kills adult ticks feeding on the deer without harming the
A more detailed story on the scientists' work appears in the March issue of
Agricultural Research, on the World Wide Web at:
Scientific contact: Pat Allen,
Parasite Biology and
Epidemiology Laboratory, Beltsville, Md., Phone (301) 504-8772, fax (301)