worms eating my plants
you help save my plants? Underneath at the roots of polyanthus and
lots of other plants is a thin clear worm 1cm long and a thin brown-striped
one about 2cm. They completely destroy the plants and there is also
a very small dark fly in masses. I use Aquaticus products and Gild
and have also tried Neem oil, but have no luck getting rid of these
pests. Hoping you can help.
not sure what the brown-striped worm is, but the smaller ones sound
like the larvae of a fly, possibly sciarid fly (sometimes called
fungus gnats) and the masses of small flies sound like adult sciarid
flies. The female fly lays eggs in wet potting mix and the larvae
feed on microscopic fungi and decaying organic matter in the mix.
They thrive in warm, moist greenhouse conditions and are seldom
a problem outdoors. They usually don't harm plants, but if for some
reason plants are already weakened, the larvae can seize the opportunity
and feed on tiny roots, making an already bad situation worse. The
presence of fungus gnats is usually a sign the mix is too wet.
One of the best ways
to avoid the problem is to use a free-draining potting mix and allow
it to dry out between waterings. Gild should kill off the adult
flies but will probably have little effect on the larvae in the
soil, which at this time of year quickly turn into adults.
To control the larvae
you could try drenching the mix with a solution of a contact insecticide
such as Pyrethrum or use a diazinon-based product like Liquid Diazinon
or No Insects Lawnguard Prills.
Gardener, Issue 166, 2005, Page 24
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.