Illinois Natural History Survey Reports

              1
ILLINOIS
NATURAL
HISTORY
SURVE Y R e p o r t s
Spring 2004
No. 379
I N S I D E
Highlights of the Long
Term Resource
Monitoring
Program at the INHS
Great Rivers Field
Station
2
INHS Researcher
Named a Fellow by The
Wildlife Society
4
Channelization, a
Major Factor Influenc-ing
Stream Condition
in Illinois
5
Critical Trends
Assessment Program
Web Page:
AWindow into Illinois
Habitats
8
Transmission Cycle of
Neospora caninum: A
Single-cell Parasite at
the Interface Between
Domestic and Wildlife
Species
9
Species Spotlight:
Devil Crayfish
10
Naturalist's Apprentice:
Crayfish Word Search
11
Continued on back page
Some plants that arrive in Illinois
from exotic homes lack natural
enemies to keep their popula-tions
in check and become inva-sive.
The teasel species
(Dipsacus fullonum [common
teasel] and D. laciniatus [cut-leafed
teasel]) are examples of
such exotic plants. These Old
World plants have been in North
America since the 1800s and in
Illinois for a number of years.
The first records of D. fullonum
(referred to as D. sylvestris) in
the Illinois Natural History Sur-vey
(INHS) Herbarium date to
1934, but teasel recently has be-come
more visible along road-sides,
pastures, and untilled
lands.
Mowing is considered to be
one of the primary means of
spreading teasel, and changes in
mowing patterns may be respon-sible
for the increased visibility.
Teasel species are monocarpic
perennials, meaning they only
flower and set seed once. Unlike
true biennials, a teasel can re-main
as a rosette for many years,
until it reaches a size at which it
bolts, flowers, and sets seed.
Continual mowing likely had
kept teasel plants small enough
that they didn’t bolt; fewer
mowings (and occurring later in
the season) have led to explo-sions
of populations of the plant
at many sites, giving the appear-ance
that it recently had arrived.
Methods for fighting teasel have
Prospects for Biological Control of Teasel in
Illinois
included cutting and
herbiciding, but
costs of labor and
chemicals, as well
as harm to nontarget
plants from
overspray, have re-sulted
in reduced
effectiveness of
these methods. Bio-logical
control is one
of the few remaining
approaches possible.
Staff from the
INHS Center for
Ecological Entomol-ogy
have developed
a partnership with
scientists at the
USDA-ARS Euro-pean
Biological
Control Laboratory
near Montpellier,
France, Millikin
University, and the
USDA-ARS Inva-sive
Weeds Research
Unit on the University of Illinois
Urbana-Champaign campus. This
partnership will, among other
activities, search for natural en-emies
of teasel in its native
range. Exploration by USDA
scientists in southeastern Europe,
southwestern Asia, and France
has already uncovered a few po-tential
arthropod agents that may
prove useful in the fight against
teasel. To date, a flea beetle
(Longitarsus strigicollis), a leaf
beetle (Galerucea pomonae), two
leafrolling tortricid moths
(Cochylis roseana and
Endothenia gentianaeana), a
nymphalid moth (Euphydryas
aurenia), and an unidentified
eriophyid mite have been found.
Further exploration in Turkey,
Greece, and Bulgaria is planned
for the summer of 2004.
Teasel offers a unique op-portunity
for biological control.
All species in the teasel plant
Brian Rector of the USDA-ARS European
Biological Control Laboratory is dwarfed by a
teasel in Greece. Photo by Rene Sforza, USDA-ARS
European Biological Control Laboratory, Montpellier, France