Friday, September 7, 2012

Moulting Phyllium monteithi

Last February an adult pair of Phyllium monteithi (Leaf insects) were found in Kuranda by an invertebrate enthusiast from Cairns. They were found upon Cape Ironwood (Gossia floribunda).  Females of this species have proved to be extremely elusive until now, but it was only a matter of time before one turned up. The many eggs laid by the female were collected and incubated. By mid-year some had hatched.

We acquired some 1st instar nymphs and some eggs about 3 weeks ago to begin our own captive population of these amazing insects.

Today the first of our hatchling (1st instar) nymphs has moulted. Here are some images of the moulting process.

Several minutes into the moulting process and the insect is pumping itself steadily out of the old exoskeleton. The initial emergence point through a split that forms just behing the head

All the legs are now free.

The insect hanging by the end of its abdomen while the new exoskeleton hardens.

All complete, and now a 2nd instar nymph.

The moulting process (ecdysis) is how arthropods achieve growth. Insects such as phasmids need to have a secure hold on a leaf or branch in order to extract themselves effectively from their old exoskeleton. If something goes wrong it can result in limb loss or even death. It is also a period where they are extremely vulnerable to predators.

This specimen moulted at 7am this morning. The temperature was 16.5°C and the process took around 20 minutes for the insect to completely free its limbs and the majority of its body. It then hung from the exuvia via the end of its abdomen for a further 20 minutes before pulling completely free and climbing back onto the leaf. Like most phasmids, it then proceeded to eat the exuvia.

If you are interested in keeping stick and leaf insects yourself, visit our comprehensive site.

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