INVASIVE ALIENS
From page 19
(Eichhornia crassipes) was in
1974 and since then a further
seven have been released, of
which six have been con-
firmed as established.
Unfortunately, Gauteng is one
of the areas where there is
considerable pollution of
water with nitrates and
phosphates which feeds the
hyacinth faster than biological
control agents can damage it,
so the approach has also
included herbicides and
mechanical means of
eradication, which is an
ongoing process.
There has been some success
against some varieties of
Lantana camara owing to the
Releasing thrips on to pompom weed
action of the suite of biologi-
cal control agents released
against it. South African
research programmes on this
specie have also benefited, or
could potentially benefit,
other countries in which
Lantana is invasive. The
natural spread of the leaf-
mining fly Ophiomyia
camarae to neighbouring
countries will have helped to
combat lantana there as well.
The leaf-feeding beetle Mada
polluta, was widely released,
including in Gauteng, in the
heartened to know that the
stem and leaf deforming
thrips that was released in
2013 has become well
established. The rust,
Puccinia eupatoria, which
invades the seeds and kills
the whole plant, including
the roots, is abundantly
wide-spread. A permit has
also been received for the
release of a flower feeder to
target pompom weed.
The seed feeding weevil that
targets balloon vine
(Cardiospermum
grandiflorum) is also well
established.
war against yellow bells
(Tecoma stans). The agent is
reported to be well estab-
lished and is being followed
Continued on page 21
up by a leaf-
miner as well.
Readers who
have been
following the
ongoing saga of
the pompom
weed
(Campulo-
clinium
macrocephalum
) will be
Megamelus scutellaris on water hyacinth
20
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