As we know, caterpillars are a larval stage of butterflies and moths (also sawfly larvae are sometimes termed caterpillars too). Whilst they aren’t strictly speaking a species in their own right, they are very characterful and interesting and it’s sometimes easy to forget that they are a butterfly or a moth in the making.
On hatching from their egg, the caterpillar’s main mission in life is to eat – and eat and eat and eat (some, like the tobacco hornworm will get up to 10,000 times their original size – wow that’ll make you feel better about any weight issues!!) Once the ultimate size is achieved, they pupate and transform into their winged adult form.
Caterpillars can be friend or foe – on the plus side: some are used as pest controls; some are seen as valuable food sources (birds, reptiles, wasps, beetles, small mammals and even us – yummy (not!) and some are employed in producing silk; but it’s not all good news – some are serious agricultural pests; some do untold damage to a variety of trees and plants and some even wreak havoc on other materials such as carpets and cloth.
Whilst the vast majority of caterpillars like plant material to munch on, a small number prefer meat (other insects) or even each other (not very friendly to your breatharian).
Caterpillars seem to be especially popular amongst children (who hasn’t had a birthday cake made in the shape of a caterpillar? Or read books about Hungry Caterpllars?) So why do they pique our interest? Could it be their pleasing, rounded shape? Maybe it’s the way they move – in that undulating motion that they accomplish by squeezing muscles one after the other (on average they have about 4,000 muscles, which is over 6 times more than we possess!); or perhaps it’s their wide variety of shapes, sizes, colours and designs?
There are some weird and wonderful specimens out there; take, for example the saddleback caterpillar, that sports a pair of horns and bristles with venomous hairs; or there’s the flannel moth caterpillar, which for all the world looks just like a toupee (but don’t be tempted to try it on because those hairs are poisonous); then there’s the spicebush swallowtail caterpillar that looks just like a little snake – it has markings that mimic a snake’s head, with eyes and a mouth! Whilst you might be thinking that these guys would only give a fright to a bird or lizard – think again – the giant silk worm caterpillar is so poisonous that it can kill a human being! So, these guys sure mean business!
Why do they go to such lengths? It’s all in the name of survival – caterpillars definitely know a thing or two about how to get by (which when you’re a sitting target for any hungry predator is a must-have feature). Some have bright markings and poisonous hairs or spines, like the garden tiger moth caterpillar; others use camouflage as an option – the unicorn caterpillar resembles a dried-up leaf; whereas the citrus swallowtail caterpillar chooses to disguise itself as bird droppings (nice!) but it works – it certainly doesn’t look appetising like that! Whilst others (if sufficiently riled) will even spit in defence (the monarch caterpillar).
The majority of caterpillars seem to prefer their own company, being solitary creatures; although certain species like to form groups – there’s safety in numbers! Birch caterpillars, for instance, will encourage others to join them by shaking and shimmying themselves around to create vibrations – they can even generate noise from their butts! They have specially adapted rear ends that they can drag across the leaf surface to put out a call to others! (that’s quite literally talking out of your backside haha!)
Moths and butterflies tend to spend longer being caterpillars than they do in their flying adult form. The woolly bear caterpillar takes this to the extreme, living for around 14 years before it eventually grows up to become a moth (this length of time is due to the harsh, freezing environment that it lives in – being forced to remain in suspended animation for a great deal of time, which slows down its growth rate).
Contrast this to the monarch butterfly caterpillar which can take an average of a mere 11 days to reach pupation – that’s fast! And whilst some monarch adults live for around 6 weeks, the final generation famously lives for up to a year, taking their annual migration to warmer climes to overwinter.
Yes, the world of caterpillars is enthralling and diverse and it’s easy to see how we regard these chaps with such fascination and enjoyment.
Time to get a wriggle on!