A Sticky Situation for Nature's Greatest Secret Agent
Somewhere amongst the leaves in your backyard is a camouflage master. Even though there are around 150 stick insect species in Australia, it’s still difficult to spot one.
The stick insect or Phasmid is a master of disguise. They remain still during the day. Look for them at night by torchlight when they’re feeding, or after a storm or a windy day when they may have been blown from their branches.
You might not be the biggest fan of insects but you’ve nothing to fear from stick insects. They’re not aggressive or venomous. These fascinating creatures are simply peace-loving vegetarians who like to keep to themselves.
In fact, stick insects are so private that they don’t like to leave a single trace of their presence. Unlike grasshoppers who leave half eaten leaves in their wake, stick insects eat entire leaves so it’s tough to spot where they’ve been.
Stick insect eggs also look like seeds. Ants carry the eggs of the Spiny Leaf Insect down into their nests and protect them from predators. When they hatch, the babies look and behave like ants until they can escape the nest and climb into a tree.
Stick insects are such amazing hiders that it’s even difficult for them to find each other. They’ve come up with a crafty solution to this problem - the females can produce young without mating. Mum will lay unfertilised eggs which later hatch into females. If stick insects mate, the eggs will hatch either males or females.
If a male finds a female out of the breeding time, he may latch onto her back and wait until it is time to breed, rather than risk losing her again amongst all the foliage.
When surprised, most stick insects will sway slightly, just like a twig caught in the breeze. Or they will drop to the ground, legs tight to the body, and remain motionless just like a snapped stick.
When very annoyed some varieties will throw open their wings, revealing a bright colour underneath, and vibrate noisily. They’ll curve angrily toward the attacker as if they’re about to sting. But never fear, it’s only a bluff.
If you’re lucky enough to spot a stick insect, don’t try to pull it from its branch or it might drop one of its legs. This is a distracting defence mechanism. Young stick insects can regrow legs the next time they moult, but a fully grown adult can’t.
DID YOU KNOW?
The biggest stick insect in Australia, discovered in 2006, is the Ctenomorpha gargantuan. It measures a whopping 61.5 cm with its legs outstretched.
Look for stick insects when pruning or removing dropped branches from your backyard. As they’re so camouflaged, it’s very easy to toss these guys right out with the garden clippings. When you find a stick insect somewhere it shouldn’t be, push up your sleeves as their little claws catch on your clothes and tear off. Put your hand or a piece of paper in front of its path and let it crawl aboard. Return it to the branch of a nearby eucalypt or wattle.