Inside a Caterpillar Cocoon? By
Rachel Ignotofsky. Crown. $18.99.
The notion of disintegrating a person’s body, transporting it, then
reassembling it, is a common one in science fiction, and it raises all sorts of
interesting philosophical questions. Is the reassembled person the same as the
disassembled one, or a copy? Does the person die when disassembled, only to be
brought back to life when reassembled? In between disassembly and reassembly,
is the person alive, dead, or something else?
Philosophers and fans of science fiction may want to turn for answers –
or if not answers, then more questions – to the everyday miracle that Rachel
Ignotofsky explores for young readers, with clarity and understanding, in What’s Inside a Caterpillar Cocoon? What
happens at the pupal stage of a butterfly’s or moth’s life is one of the more
extraordinary occurrences involving life on our planet: the larval form
(caterpillar) essentially disintegrates into its component molecular parts,
becoming what is basically a soup – out of which, astonishingly, the entire
insect is rebuilt into an altogether new form that is made of exactly the same
materials but that looks and functions entirely differently.
This is one of those things that become more astonishing the more you
think about them. From a plump, multi-legged, earthbound crawling creature
comes a delicate, winged flying insect – thanks to a metamorphosis that we
humans still do not fully understand. Ignotofsky does an excellent job of
explaining how this life cycle works, making the underlying science (which is
intriguing enough on its own) even more appealing to young readers by giving
her portrayals of caterpillars, butterflies and moths anthropomorphically
expressive faces. As she explains this fascinating life cycle, she throws out
facts that make things even more interesting: “Butterflies and moths are both
the only insects with scaly wings,” for instance.
Ignotofsky also explains something that even most adults may not know:
the difference between a cocoon (in which moth caterpillars transform) and a
chrysalis (in which butterfly caterpillars change their form). She also
discusses the similarities between butterfly and moth caterpillars: one fine
full-page illustration points out how caterpillars possess the three typical
body parts of insects (head, thorax and abdomen) while also showing a
caterpillar’s three pairs of true legs and its prolegs (“two to five pairs of
stubby unsegmented ‘fake’ legs for climbing”). And Ignotofsky portrays the very
wide variety of caterpillars in pictures that are specifically designed to
accentuate the differences among, say, the woolly bear and royal walnut
caterpillars of moths and those of the spicebush swallowtail and zebra longwing
Little bits of information on survival traits are neatly incorporated
into this fascinating science book: the false eyespots of the elephant
hawk-moth make it look like a snake, scaring predators away; the monarch
butterfly caterpillar has a pattern that warns that it is poisonous if
consumed; the inchworm (geometer moth) spins a line of silk and leaps into the
air from a branch if threatened by a predator. Although the illustrations are
not fully realistic, they are highly effective in pinpointing appearances and
behavior patterns that can be very difficult to see in the real world – exposing
young readers to the marvels of some insects that only seem commonplace until
you examine them more closely.
In addition to discussing butterflies’ and moths’ life cycles, Ignotofsky explains their ecological importance even as she pinpoints some of their differences: butterflies, for example, almost always live by drinking nectar from flowers, while moths have much-more-varied food habits, with some drinking as butterflies do while others chew on plants and some lack mouthparts altogether, so they never eat after they transform to their adult phase. “Many wildflowers, trees, and crops depend on insect pollinators,” Ignotofsky writes, urging young readers to grow insect-friendly gardens and learn how to protect nature so cycles like those of butterflies and moths can continue to take their natural course. At the back of the book, she offers a small sample of further resources that interested readers can consult for more information – the start, hopefully, of engaging the human ability to transform scientific knowledge into supportive activities that will allow caterpillars and the butterflies and moths they become to prosper for many years to come.