1. Good Organic Gardening - January-February 2016

SAFER SOLUTIONS | Dipel
Green looper caterpillar
nothing but leaf skeletons (and lots of
green droppings!).
Cabbage moth caterpillars are around
1cm long, green to brown coloured and
will curl up if disturbed. Cabbage moth
populations tend to increase during dry
conditions and the caterpillars enjoy
feeding on brassica vegetables as well as
flowers in the brassica family, such as stock.
Armyworm caterpillars are most often
found in lawns, but there are some types
of armyworm that will attack vegetables
like corn, beetroot and tomatoes and
will also eat both flowers and foliage of
ornamental plants. Young armyworm
caterpillars are green and turn brown and
striped as they mature.
Budworm caterpillars (Heliothis)
grow to around 4cm long and can be yellow,
green or brown with white and dark stripes.
Budworms commonly feed on tomatoes and
corn but can also eat through rosebuds,
geraniums and petunias.
Green looper caterpillars, which are
bright green with white stripes, can be
found on roses and other flowers as
well as fruit and vegetables including
silverbeet, lettuce, brassicas, beans,
tomatoes and strawberries.
When there are only a few caterpillars,
you can just pick them off by hand (though
they can be masters of camouflage and
concealment) and also make a juicy meal
for birds. Caterpillars also have some natural
insect enemies, such as parasitic wasps and
flies, predatory shield bugs and assassin
bugs, which can help reduce caterpillar
populations. So it’s good to encourage them
to your garden. The beneficial nematode
Steinernema carpocapsae is a natural
predator of armyworm.
However, when caterpillar numbers are
significant and you want to be able to harvest
some of your much-loved herbs and vegies
rather than just provide a rich source of
caterpillar food, a Bt insecticide provides
an environmentally soft option to keep
caterpillars under control.
There are Bt-based insecticides available
to home gardeners that are certified
organic by Australian Certified Organic.
Assassin bugs (Pristhesancus plagipennis)
help to control caterpillars
So organic gardeners can use a naturally
derived, organically certified way to control
caterpillar pests.
When there are only
a few caterpillars, you
can just pick them off by
hand (though they can be
masters of camouflage and
concealment). They also
make a juicy meal for birds.
James Niland CC
60 | Good Organic Gardening