6. Good Organic Gardening - November-December 2016 AvxHome.in

PEST PATROL | Beneficial insects
Earwigs; Order:
Dermaptera
These little insect species can sometimes
get a bad rap because they can often cause
small amounts of damage on seedlings,
fruit and plants. They redeem themselves,
though, by also causing havoc for a range of
nuisance garden pests such as caterpillars
and sap-sucking insects, and they also feed
on garden waste.
The name earwig has long caused people
to have horrible visions of these small brown
insects crawling into people’s ears, but
this doesn’t happen as they have far more
favoured dark, moist locations in our gardens
to frequent.
Spiders; Order:
Araneae
Most people have an inherent dislike of these
eight-legged arachnids but every gardener
should be grateful for having a certain
number of species in their backyard.
Most spider species are not aggressive
and would rather move on than interact with
us. Common species such as orbs, jumping,
flower, net casters, huntsmen, leaf curlers and
daddy long legs are sometimes hard to find,
as they are busily going about their business
out of view.
Some species are more active at night,
taking advantage of the night-flying insects
by building their webs on dusk, ready for an
evening catch. Other species are more mobile
and ambush their unsuspecting prey by
hiding on plants, logs, leaf litter and so on.
Some spider species can even change
colour to attract their prey, while others
have camouflage tactics to make them
harder to spot by either the prey they are
trying to catch or by even larger predators
such as lizards, birds and wasps trying to
predate on them.
All in all, spiders will consume a vast
number of insects in your garden.
Wasps; Order:
Hymenoptera
There are literally thousands of species
of wasps — in Australia alone, there are
more than 10,000 and most of us nonentomologists
think of them as insects that
sting, even though there are actually only a
few species that have that capacity when
they feel threatened. Many are very beneficial
to have in the garden.
Most wasps are nectar feeders as adults
but as larvae they are voracious meat eaters!
It’s a bug-eat-bug world out there.
Some parasitic wasps will actually lay their
eggs inside living caterpillars, bee and wasp
larvae — even spiders — without the hosts
even being aware that they have become
living incubators. The wasps do this by
paralysing their victims with venom first. The
eggs then eventually hatch and eat the host
from the inside out, finally bursting out once
they have reached adulthood.
There are even parasitic wasp species that
parasitise other parasitic wasp species!
Common wasps in Australian backyards
Ichneumon: This group have very distinctive,
long antennae that they use to seek out
larvae hiding in plant stems, logs and so forth.
They are stingless and can parasitise large
numbers of pest species within the garden.
Lawn grubs are fair game.
Paper: Colony wasps that create paperylooking
nests out of saliva and wood,
they feed their young on partially eaten
caterpillars and insects.
Mud Dauber: These are solitary wasps that
make small egg cases out of water and mud.
They place parasitised spiders and caterpillars
in these mud cases and seal them in.
Cuckoo: These wasps invade other wasps’
and bees’ nests and parasitise their larvae.
Spider: These species paralyse spiders,
parasitise them and then imprison them
inside their egg cases and nests.
Mud Dauber wasp
Australian native earwig
(Labidura truncata), by far
the commonest species
Garden orb weaver spider
(Eriophora sp.)
Donald Hobern, CSIRO
60 | Good Organic Gardening