NEWS
Pompom biocontrol thrips catches on
H
ow bad is the
pompom weed
(Campuloclinium
macrocephalum) infestation
where you are this year?
For the past few years the use
of a biocontrol agent against
the plant has been applied in
Gauteng and it is instructive
to gauge its efficacy and
success.
The biocontrol agent in
question is the South
American thrips Liothrips
tractabilis which lives on and
attacks only pompom weed.
The ARC Plant Protection
Research Institute's Liamé van
der Westhuizen reports that
“where the insects have been
established over two to three
seasons, we have recorded a
reduction in height as well as
in the number of buds per
inflorescence.”
This is good because a
reduction in height is a sign
that the plant is under stress
and the reduction in the
number of buds will over time
A sea of pompom weed in the Rietvlei Nature Reserve
11
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also impact on the seedbank.
She goes on to say, “Liothrips
is in some instances also
preventing plants from
flowering altogether. The
insects are however slow
dispersers and the population
needs to build up over a
number of seasons before
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