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Posts tagged “Cecropia Moth

Cecropia Moths Pupating

11-11-13 cecropia cocoon dissected  056Our largest North American native moth, the Cecropia Moth, Hyalophora cecropia, spends the winter as a pupa inside a cleverly-crafted 3” – 4”-long shelter, or cocoon, which it creates and attaches lengthwise to a branch while still in its larval stage. The Cecropia caterpillar, with the silk glands located near its mouthparts, spins not one, but two silk cases, one inside the other. In between the two cases, it spins many loose strands of very soft silk, presumably to enhance the insulating properties of the cocoon. Inside the inner case, the caterpillar splits its skin and transforms into a pupa. Come spring, an adult moth will emerge from the pupal case and exit the cocoon through one end which was intentionally spun more loosely, allowing the moth to crawl out the somewhat flexible tip. (Note: dissected cocoon was not viable.)


Cecropia Moth Cocoon

This past summer there seemed to be more giant silkmoths than usual, including Cecropia Moths (Hylaphora cecropia).  (see ). Assuming many of these moths bred and laid eggs, and that most of the larvae survived, there are probably a large number of Cecropia cocoons in our woods.  Even so, it is not an easy task to find them, as they are so well camouflaged, and are often mistaken for a dead leaf.  Cecropia caterpillars spin silk and fashion it into a three-inch long, tan cocoon (giant silkmoths make the largest cocoons in North America) which they attach lengthwise to a branch or stem.  There is a tough but thin layer of silk on the outside, which protects an inner, thicker and softer layer of silk on the inside.  The caterpillar enters the cocoon through loose valves it makes in both layers, which are located at the tip of the cocoon’s pointed end.  Shortly after the larva crawls inside both of these layers, it pupates.  Its skin splits, revealing a dark brown pupa. For the rest of the winter and most of the spring, it remains a pupa.  In early summer it metamorphoses into an adult moth and exits the cocoon through the same valves  through which it entered.


Cecropia Moth

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Cecropia Moth Caterpillar Molting

The caterpillar, or larval, stage of a butterfly or moth is the only stage in which the insect has chewing mouth parts.  Hence, it is the stage during which a great deal of eating takes place.  As the caterpillar eats, it grows larger, and eventually molts its skin, revealing a new, larger skin underneath the old.  A cecropia caterpillar molts four times before spinning its cocoon and pupating. The cecropia caterpillar in this photograph has just molted its skin, which is attached to the plant just above the caterpillar’s head. If you look closely, you can see where the colored tubercles were.  Within an hour of when this photograph was taken, the caterpillar had eaten its skin.


Cecropia Moth Caterpillar

The larval stage of the Cecropia Moth ( Hyalophora cecropia), a giant silk moth, is a sight to behold.  The yellow, blue and red knobs that adorn its 4″ pale green body are striking.  Look for this caterpillar on apple, ash, box elder, cherry, lilac , birch, maple and poplar trees, whose leaves it consumes with relish.  The larva spins a brown, spindle-shaped, 3” cocoon in the fall, and overwinters as a pupa inside it.  In the spring, the adult Cecropia Moth , North America’s largest native moth, emerges.  Brown, with a 4” to 5” wingspread, it has no mouthparts, and lives only about a week to ten days, during which time the males mate numerous times, and the females lay eggs. Unfortunately, this species of moth seems to be declining in number, in part because it suffers from parasitism by a fly that was introduced to control the Gypsy Moth.



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