‘Leaf’ Me Alone…

May 14, 2010 at 12:31 am | Posted in itchy fingers | 6 Comments
Tags: Animals, Bugs, Education, Nature

Recently while looking for birdies at Sungei Buloh, Itchyfingers had a surprise find. Initially we did not know what exactly was this, cos we have not seen anything like this. Tisu Boy speculated it could be some kinda ant mimicking some other insect, but the more I looked at it, the more familiar I found it…It looked remotely familiar as somehow it reminded me of the ones I have to handle at the volunteering programme I joined…I even cut up one dead specimen…But I couldn’t be sure at the moment…cos we really did not know or heard of its existence in Singapore.

So what did Itchyfingers find?

It was tiny…I wouldn’t have spotted it if not for the fact that I was bored while waiting for the nearby pair of nesting birdies to show themselves and started looking around the foliages for interesting insects to shoot. I was shooting a tiny grasshopper when suddenly I saw this guy on a thin vine…

It was motionless…this tiny guy looked flat from the side…its limbs
were also broad and flattened

The antenna were short and the rear end was in a curled up posture. Now
this posture certainly looked very familiar! It was one of the tactics used in
my other more familiar insect when it feels threatened. By curling up the
tail, they look bigger, like that of an attacking scorpion about to strike…

Tiny it might be, he was obviously trying to tell me not to mess with him and leave him alone…and it started to move very slowly towards the leafy part trying to hide itself…now could my suspicion be correct?

A Leaf Insect!!! It had to be a Leaf Insect! Who else looked so similar? This
should be a juvenile?

I was so excited! We didn’t know and have never seen a life Leaf Insect other than captived ones in zoos or dead specimens in museums; neither did we hear of anyone in Singapore finding one in our forests or reserves. So it was such an exciting moment for us! By now the tiny guy was motionless again…he must have been thinking that he’s well camouflaged and with his scarily curled up tail, he would be left alone now… Too bad we didn’t have the correct lens to take macro shots of this interesting guy – Tisu Boy had his long lens for birdies and all I had was the compact digital camera…No choice, gotta make do and keep taking more shots in order to get at least one decent shot… 😮

My little itchyfinger as a scale of measurement against the Leaf Insect…
it should be around 2 cm from forelimb to tail, if uncurled….

Well, we left him alone when the birdies came back…after they flew off again, I went back to check out the Leaf Insect only to find him gone… 😦

To confirm our findings, Itchyfingers headed for the library after lunch and checked out the local guidebook, “The Stick & Leaf Insects of Singapore” by Francis Seow-Choen. I was right! It was a nymph of Phyllium siccifolium, or Linnaeus’ Leaf Insect. It says that, “the females of this species create a stridulating sound when handled and will also use her legs to grip tightly around any intruder attempt to pick the insect up. This species is usually green although yellow specimens have also been found. Males are 53 – 57 mm and females are 70 – 90 mm in body length.” Wow! That is big!

Leaf Insects and Stick Insects belong to the order Phasmatodea (or Phasmida). As the names suggested, Phasmids are insects that look like leaves, twigs and sticks. Because of these resemblances and the fact that they are nocturnal, it is very difficult to find  phasmids when they are so well camouflaged in the wild. Itchyfingers have only saw a wild Stick Insect in Singapore twice, and once in Malaysia while we have never seen a wild Leaf Insect.

A walking stick found at Taman Negara some years back…Twice when I
saw them in Singapore, they all flew off before I could take any photos.
Most (but not all) of the flying ones are males. This one should be a female
looking at the rear end now – it has a ovipositor for laying eggs…
If not for the fact that she made a mistake by staying on a piece of leaf
and swaying left and right the way twigs move when blown by wind, we
would not be so lucky as to spot it! Notice the first pair of legs are longer
and stretched out…an attempt to look even more like a stick…Sometimes
they are so stretched that they looked as if they only have four legs

She realised her mistake and moved underneath the leaf looking for a twig.
Itchyfingers, being itchy fingers, remembered this very first time stroking
a life and wild stick insect..Feel exactly like a stick! 😀

A captive Giant Prickly Stick Insect from Australia on my hand…See how
the lobed legs resemble that of the Leaf Insect nymph? They may look
menacing, but Stick Insects are harmless…

The head also look similar…Like Leaf Insects, the chewing mouth parts
of Stick Insects consists of four long, thin jointed hairy structures at the bottom
used to taste leaves…Itchyfingers showed the picture of the mouth part of
another species of stick insect, the Jungle Nymph on our earlier post here…

Like some species of Stick Insects, some species of Leaf Insects will lay their eggs in moist soil. When the eggs hatch, the nymphs look like miniatures but not exact duplicates of the adults. They would hurry off to look for their food plant in order to feed, and would gradually change into a green colour within a few days. Maybe that explained why when Itchyfingers went back the following week we couldn’t find any more nymphs…It could have already turned colour and so well camouflaged or it could have found its food plant elsewhere.

A beautiful Leaf Insect, Phasmotaenia lanyuhensis, from the Insectarium
of Taipei Zoo. The nymph we found would have grown into a similar leaf-
like adult…

Itchyfingers certainly hope to see the adult Leaf Insect one of these days! And we shall definitely keep our eyes wide open for any suspicious leaf movement from now on! :p

Also see related posts:
> Master of Disguise and Camouflage
> Touch No Evil
> Attaining Immortality – Body Preservation