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Leaf & Stick Insects
 The
leaf insects hang from the underside of leaves in the trees and
might look like a dried dead leaf at first. They can be very large
- up to 25 cm (10 inches) - but most are about 10 to 14 cm (4 to
5 inches). They tend to change their colour according to where they
are so the leaf insects can range from pale green to dark brown
or they can be blotched to simulate lichen on a tree trunk, for
example.
The stick insects (also known as phasmatids) are
more diverse and range in size from 10 or 15 cm (4 to 6 inches)
to a recently discovered giant stick insect which measures 52 cm
(21 inches)! While most species are a drab colour, there is one
stick insect from the Wet Tropics rainforests which is a stunning
sky blue.
The Peppermint Stick Insect
 The
Peppermint Stick Insect (Megacrania batesii) has a very small
and patchy distribution along some beach areas in Cape Tribulation,
Innisfail and Mission Beach. It feeds only on a few species of Pandanus
plants and these spikey-leaved palms also provide some shelter from
predators. The Peppermint Stick Insect spends all its time on the
Pandanus, feeding, sheltering, mating and laying its eggs on the
leaves where they roll down to the tight-fitting leaf axil to 'incubate'.
Why is it called the Peppermint Stick Insect? As a defense mechanism,
it sprays an irritating fluid at any predators (which include curious
tourists) and this fluid smells like peppermint. This is a strenuous
act for the frightened stick insect so if you are lucky enough to
find one in your travels through the Wet Tropics, please don't try
to touch it.
Most species of stick insects live in the trees,
feed on the leaves and look just like a branch. The easiest way
to pinpoint one is to look for a branch that seems out of alignment
to the other branches or a branch that appears to be attached to
the outside edges of leaves.
The female's body is much larger than the male's
and both have wings - but the males' wings are larger. Females don't
travel around much and emit a hormonal perfume (called a pheromone)
to attract the males to them for breeding. The males have larger
wings to enable them to fly longer distances in search of females.
Although the stick insects are well camouflaged
to aid their invisibility to predators such as birds, their wings
provide a backup defence system. Normally, their wings fold up very
neatly along the body but the stick insect can spring the wings
out suddenly. The colours of stick insect wings can be vivid colours
which can startle a potential predator momentarily - just long enough
to enable the stick insect to fly away.
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