Page 21 - The Book of Caterpillars: A Life-Size Guide to Six Hundred Species From Around the World

THE MIRACLE OF METAMORPHOSIS

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generally used for hard-cased butterfly pupae or the casing itself, while ABOVE The Lime
Butterfly (Papilio
many moths spin a protective outer silk “cocoon” around themselves. demoleus) makes
its remarkable
Pupae are formed in one of five basic modes: loose on the ground, within transformation from
the final “pharate”
a silken cocoon or leaf shelter, underground in an earthen cell, hanging by pupal stage to flying
adult. The cells
the terminal end (cremaster) attached to a silk pad, or attached upright within the pupa have
regrouped into adult
by the cremaster with a supporting silk girdle. Loose pupae are common form but initially
remain enclosed
in moths but rare in butterflies. Skippers—butterflies from the Hesperiidae within the chrysalis.
As this shell becomes
family—commonly form pupae within tied leaf or grass shelters, while more transparent,
the maturing adult
hanging pupae are characteristic of Nymphalidae butterflies, and girdled uses its feet to break
free and extricate
pupae are found in species from the butterfly families Papilionidae, itself. Next, it hangs
from the pupal shell
Pieridae, and Lycaenidae. While some moth larvae spin cocoons on leaves, or nearby substrate
as the new wings
twigs, or branches, many burrow in leaf litter or to varying depths in the dry and stiffen, and
prepares its proboscis
ground. Several species incorporate protective materials with their silk for sucking nectar
from flowers. It may
into the cocoon to strengthen it, such as chewed bark and their own stinging take up to an hour
before it is ready for
setae. Others add twigs or bits of vegetation to help disguise the cocoon. its first flight.
When a pupation site is selected, and silk pads, shelters, or cocoons are
complete, the prepupal larva shrinks a little and waits motionless for the
final molt to occur. The outer skin then softens, splits, and falls away,