There
is still somewhat of a shortage of good scientific research material
on lace bug however, we have outlined some basic specifications
of the problem below.
The
olive lace bug is one of the two simple sucking insects that can
reduce the vigor of olive trees. The first one is the brown
or black olive scale (See OLIFAX 13). The lace bug is flat with
lace-like wings, and is no more than 2mm in length. It resides
on the underside of olive leaves.
The
first and very obvious clue that lace bug is present, is arusty
yellow spotting noticed on the top side of the leaves. The spots
are about half the size of a pin-head and there can be up to one
or two hundred on a single leaf. The small yellow spots
are easy to see as they contrast clearly against the otherwise
dark green leaf surface.
The
main secret to avoiding pest problems is to keep your olive trees
in good health but even this is not a guarantee. We have
noticed around the industry that the healthier the trees are kept,
the lower the incidence of lace bugs and other insects. Old, neglected
trees, badly stressed as a result of water shortage and
lack of nutrients will be more affected by lace bug.
We
have also noticed that trees which are not growing well due to
poor land preparation prior to planting or nearness to large
eucalypts are also more susceptible to problems.
One
spray of a suitable systemic insecticide will be adequate to completely
kill the insects. If the trees have been badly neglected, and
infestation is severe, then a second spray two weeks later
may be necessary. After that, it will probably be twelve months
before the trees need checking again.
To
reduce the problem in the future, make sure that the trees are
kept in good health with adequate fertiliser, pruning and
water. Systematic pruning will also open the tree up to
let the sun in. Dead and unwanted branches should be removed to
further improve the health of your trees.
[IMPORTANT:
Due to the chemical nature of the insecticide treatments,
Olives Australia is unable to recommend dosages or chemicals to
be used. Please check with your agricultural chemical supplier
as to the suitability for olives, method of application
and safety precautions needed for the following: Supracide
or Lebaycid. Your local agricultural chemical wholesaler will
let you know if these chemicals are registered for use in your
state and the product label will give you the quantity to use.]
See
Australian Olive Grower Issue 9 page 15 and Issue 14 page 8 for
further Olive Lace Bug research (available to purchase from our
office).
