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Nodding thistle seed-head weevil,
Rhinocyllus conicus
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Alternative Names: musk thistle
Background
Nodding thistle, Carduus nutans, is a biennial plant
native to Europe, Asia Minor and North Africa. It was first
recorded in Australia in 1950. Although infestations are limited
to the northern and southern tablelands of NSW, with localised
infestations in SE Queensland, Victoria and Tasmania, nodding
thistle has potential to spread much further. In Australia
there are thousands of seeds per square metre of soil with
seeds able to remain viable for ten years or more.
The Project
Biological control of nodding thistle started in the mid
1980s with work in Australia commencing in 1987.
There have been three biological control agents released.
The first, thistle-head weevil Rhinocyllus conicus,
has now spread on its own to most nodding thistle infestations.
Whilst its impact is great in the early part of the season
it does not control seed production later in the season. The
remaining two agents, Urophora
solstitialis (the seed fly)
and Trichosirocalus mortadelo
(the rosette weevil) were actively distributed and are
now quite widespread.
Biological Control Agents
Redistribution
Nursery sites - establishing
a nursery site for the biological control agents.
Key People
Anthony Swirepik
CSIRO Entomology
GPO Box 1700
Canberra ACT 2601
AUSTRALIA
Ph: +61 2 6246 4252
Email: firstname.lastname@csiro.au
More Information
Biocontrol halts the
spread of nodding thistle pest (PDF 105Kb)
Insect attack takes hold
of nodding thistle (PDF 63Kb)
Weevil found on spear
thislte (PDF 82Kb)
National Weeds Strategy
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