Tuesday, March 8, 2011

Beautiful and Deadly

Hey guys!

There is perhaps no other insect I am as fascinated in raising as that of lepidoptera, or butterflies and moths. Aside from the natural miracle that seems to be the caterpillar's transformation from a grub-like creature into a winged beauty, caterpillars are in fact themselves extremely fascinating and interesting creatures to observe. Amongst some of the things I like observing most in my caterpillars are perhaps their defense mechanisms. Over the entire length of their evolution, caterpillars have developed a myriad of traits to protect themselves from would-be predators. Larvae of the lycaenid butterfly for example enlist the care of subtarannean ants, who protect them and care for them during their entire metamorphosis into adult butterflies.
lycaenid larva tended to by ant
Yet, it should seem that many other caterpillars practice more conventional methods of defense, namely camoflauge or disguise, whereby the insect adopts cryptic coloration and bodily textures which allow them to blend, almost seamlessly into the vegetation around them. Some, such as the earlier instars of swallotwail butterflies, even adopt the appearance of known-distasteful matter such as bird droppings! On the other hand, there are groups of caterpillars which are remarkably beautiful and yet, it is perhaps taught to all of us at a young age that such caterpillars should only ever be looked at, and not touched. And this is one of them

Tussock moth caterpillar
This, my friends, is the larval form of the Tussock Moth. While rather unimpressive as an adult, the caterpillar of the tussock moth is perhaps one of the most elaborate and fancy caterpillars one can normally find in one's garden. It's long and lithe body lined with tufts of elaborately arranged fur, the tussock moth often reminds me of nothing more than a couture model strutting down the runway as it crawls leaf-to-leaf on our little apple tree. One might wonder if being so flashy is not in fact hazardous to the caterpillar's health as it may be spotted more easily by birds which might want to eat it but in actual fact, the tussock moth larva is one of many others which possess poisonous features which have marked it (and the rest of its species) as dangerous or distasteful to other animals. The fur of this caterpillar, for instance, have urticating qualities and can cause severe irritation and/or pain when in contact with the skin, eyes or if inhaled.

Tussock moth larva spinning a cocoon
Like most moths, the tussock moth larva spins itself a silken cocoon prior to its transformation into an adult. However, unlike the cocoons of other moths, this larvae has yet another added advantage. The poisonous fur which protected it throughout its entire life as a larvae will now provide it a final defense. As the caterpillar sheds its skin, the poisonous furs get incorporated into the silken tangle of the cocoon providing an additional barrier between the developing insect within and predators during this, it's most vulnerable time.
Closeup of cocoon showing meshwork of urticating hairs.
And so another life-cycle draws to its next stage, slightly closer to its conclusion. And so is mine, if one thinks about it. Graduation tomorrow! Might as well slap a smile on my face and enjoy the entire experience, although I must say, all this anxiety and stress is making me break out. More pictures and updates when this moth emerges and (I have been told) females continue to benefit from the poison of said furs as they collect it upon emergence and store it in their abdommens only to be used again to provide defense to their newly birthed young when they next lay their eggs. Interesting isn't it?

Oh your God. Graduation is tomorrow!

1 comment:

Nature Rambles said...

Hi Cyren! I know I haven't visited you in a while. I've been more active on my other blog than on Nature Rambles.

I was just wondering how graduation day went. Must have been better than what you'd posted (huge hassle and all that). Anyway I can't wait to hear about it. I'm catching up on your older posts now and I must say I'm enjoying it as usual. BTW, the Tussock moth caterpillar must be the diva of all caterpillars. Splendidly showy!! I didn't dare click on the picture...I get the creeps, y'know!