Moths of the Limberlost | Page 4

the first caterpillar I found in this state was lost to me
and threw it away. A few words would have saved the complete history

of a beautiful moth, to secure which no second opportunity was
presented for five years.
Several works I consulted united in the simple statement that certain
caterpillars pupate in the ground.
In Packard's "Guide", you will find this--"Lepidopterous pupae should
be...kept moist in mould until the image appears." I followed this
direction, even taking the precaution to bake the earth used, because I
was very anxious about some rare moths. When they failed to emerge
in season I dug them out, only to find that those not moulded had been
held fast by the damp, packed earth, and all were ruined. I learned by
investigation that pupation takes place in a hole worked out by the
caterpillar, so earth must touch these cases only as they lie upon it. The
one word 'hole' would have saved all those moths for me.
One writer stated that the tongue cases of some pupae turn over and
fasten on the back between the wing shields, and others were strangely
silent on the subject. So for ten months I kept some cases lying on their
backs with the feet up and photographed them in that position. I had to
discover for myself that caterpillars that pupate in the ground change to
the moth form with the feet and legs folded around the under side of the
thorax, the wings wrap over them, and the tongue case bends UNDER
and is fastened between the wings.
For years I could find nothing on the subject of how a moth from a
burrowing caterpillar made its appearance. In two recent works I find
the statement that the pupa cases come to the surface before the moths
leave them, but how the operation is performed is not described or
explained. Pupa cases from earth consist of two principal parts: the
blunt head and thorax covering, and the ringed abdominal sections.
With many feeders there is a long, fragile tongue shield. The head is
rounded and immovable of its own volition. The abdominal part is in
rings that can be turned and twisted; on the tip are two tiny,
needlesharp points, and on each of three rings of the abdominal shield
there are in many cases a pair of tiny hooks, very slight projections, yet
enough to be of use. Some lepidopterists think the pupa works head
first to the surface, pushing with the abdomen. To me this seems

impossible. The more one forced the blunt head against the earth the
closer it would pack, and the delicate tongue shield surely would break.
There is no projection on the head that would loosen or lift the earth.
One prominent lepidopterist I know, believes the moth emerges
underground, and works its way to the surface as it fights to escape a
cocoon. I consider this an utter impossibility. Remember the
earth-encrusted cicada cases you have seen clinging to the trunks of
trees, after the insect has reached the surface and abandoned them.
Think what would happen to the delicate moth head, wings, and downy
covering! I am willing to wager all I possess, that no lepidopterist, or
any amateur, ever found a freshly emerged moth from an underground
case with the faintest trace of soil on its head or feet, or a particle of
down missing; as there unquestionably must be, if it forced its way to
freedom through the damp spring earth with its mouth and feet.
The point was settled for me when, while working in my garden, one
came through the surface within a few inches of my fingers, working
with the tip of the abdomen. It turned, twisted, dug away the dirt,
fastened the abdominal tip, pulled up the head, and then bored with the
tip again. Later I saw several others emerge in the same way, and then
made some experiments that forever convinced me that this is the only
manner in which ground pupae possibly could emerge.
One writer I had reason to suppose standard authority stated that
caterpillars from Citheronia Regalis eggs emerged in sixteen days. So I
boxed some eggs deposited on the eleventh, labelled them due to
produce caterpillars on the twenty-seventh and put away the box to be
attended on that date. Having occasion to move it on the twentyfourth, I
peeped in and found half my caterpillars out and starved, proving that
they had been hatched at least thirty-six hours or longer; half the others
so feeble they soon became inactive, and the remainder survived and
pupated. But if the time specified had been allowed to elapse, every
caterpillar would have starved.
One of the books I read preparatory to doing this work asserts
concerning spinners: