The Cross Breed…?

March 14, 2012 at 11:54 am | Posted in itchy fingers | 2 Comments
Tags: Animals, Bugs, Nature, Uniquely Singapore

Itchyfingers saw this last year but we didn’t know its ID. Later, Tisu Boy saw a similar picture online and found out it is the larva of the moth Homodes bracteigutta. But I still wasn’t too sure of the ID cos I couldn’t find information on both the larva and adult except this one from Australia. So it was being shelved and slowly forgotten…until I saw a photo by this photographer asking for the ID. Was tempted to share what we found but didn’t do so cos I was not sure. Luckily a lady replied, and attached a most useful link of a scientific paper that finally confirmed its identity.

So what was it that made Itchyfingers so doubtful?

It was clearly a caterpillar, as it had both pairs of true legs and prolegs

It certainly moved like a caterpillar too! But it also looked like something else!

What made this Homodes bracteigutta caterpillar look menacing is that, 
unlike some other caterpillars with hair or spikes on the bodies which make 
them appear bigger or serve as warning sign so as to frighten away potential 
predators, this one kept moving and vibrating its setae (stiff hairlike or bristlelike 
structure) in an “almost rhythmical fashion, with abrupt and alternate raising/
lowering of the structures”. This reminded us of the Weaver Ant, and that
ant-mimicking spider which Itchyfingers saw preying on a Weaver Ant some
time ago! The constant jerking of these structures made shooting a sharp picture
of it a real challenge! 

Close up of the head with the many pairs of slender, elongated setae. As described
on the scientific paper, “the most prominent pair rises over the caterpillar‘s
head and terminates in a purplish brown, bulbous tip. The other setae are
orange brown and blade-like, radiating from the thoracic region and extending
beyond the head.” The bulbous tip really looked like those found in spiders!

Close up of the posterior rear end with the pairs of prolegs. These prolegs 
would disappear during the metamorphic stage when it changes from its larva 
stage (caterpillar) to the adult stage (moth). Both the anterior and posterior ends
look like the head of the Weaver Ant, and here you can even see “a pair of strategically
placed black dots on the anal segment that resembles the eyes of a weaver ant”! 
Our photo doesn’t show it, but “the parted anal prolegs stimulate an ant‘s wide- 
opened mandibles.” Great mimicry of the weaver ant!

Incidentally, where we found this caterpillar, there were a few Weaver Ants’ nests on the same plant. Amazing thing was, the ants moving around the plant did not seem to notice this guy here and simply bypassed it. Was it because it looked like them or was it because it looked too fearsome? Definitely a smart move to mimic and stay close to these aggressive ants for protection!

Also see related posts:
> Living in a Cage
> Eating Its Own Kind? – Spidey Galore #2
> Jaws – Spidey Galore #1
> Mystery of a Caterpillar