Page 23 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

THE MIRACLE OF METAMORPHOSIS

at the larval stage, which will now develop into adult body parts. In some

species, this metamorphosis is rapid, taking as little as five to seven days.
In others, pupae oversummer and overwinter in a dormant state, or
diapause, sometimes for two or three years. A few days before a butterfly
or moth emerges, or ecloses, the pupa darkens, indicating the advanced

stage of development. On the final day, as the shell becomes increasingly
transparent, first the patterns and color of the wings, then the rest of the
body, can be seen. At this “pharate” pupa stage, eclosion is just hours away,
and pupae that will become females may well already have males, attracted BELOW A newly eclosed
butterfly, Lorquin’s
by pheromones, in attendance. Indeed, in a number of Heliconius butterfly Admiral (Limenitis
lorquini), hangs
species, males are known to compete for a chance to mate not only with beneath its discarded
chrysalis, with 21
21
newly eclosed females but also with pupae at the pharate stage. beautifully marked
wings still folded as
In many butterfly species, adult eclosion is synchronized to occur early it waits to make its
first flight. The North
in the morning, often soon after dawn, presumably to optimize a successful American species,
a member of the
emergence, post-eclosion drying of wings, and inaugural flight. Night- Nymphalidae family,
flying moths often eclose around dusk. Eclosion begins with the butterfly is usually on the wing
between April and
or moth pushing with its feet against the shell covering the legs, antennae, October, depending
on its region.
and proboscis; to soften the toughest cocoons,
such as those made with silk and chewed bark by
“kitten” moths (Furcula species), the adult first

ejects an acid solution. Once the legs are free, the
adult grabs hold of the shell, pulling out the rest
of the body until the entire butterfly or moth is
fully extricated. Hanging and girdled pupae

species, which emerge substantially aided by
gravity, then usually hang from the pupal shell or
a nearby support, while butterflies and moths
eclosing from pupae on or near the ground
wander for a short while to find an appropriate

support site. Once a site has been chosen, the adult
begins pumping its wings to full size and sets
about zipping together the two parts of the coiled
proboscis to form a tube for sipping nectar—a

vulnerable period lasting from 5 to 15 minutes.
The wings may remain limp and flaccid for
another hour or so, depending on the ambient
temperature—then, its amazing transformation
complete, the adult flies.