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Archive for January 6, 2023

Promethea Moths Pupating

Now is a perfect time to look for cocoons, with leaves off deciduous shrubs and trees. Giant silk moth cocoons are especially evident, due to their large size (often 2″-4″).  The Promethea Moth caterpillar (Callosamia promethea), one of several giant silk moths in the Northeast, hatches in the summer and reaches its full size by fall.  It then chooses a leaf and reinforces the leaf’s stem, or petiole, with silk so as to make it less likely that the leaf will detach from the branch it is growing on.  The caterpillar then spins its silken cocoon inside the curled leaf, and spends the winter pupating inside the cocoon. Look for their well-camouflaged cocoons on low-hanging branches. 

Come May or June, the moth will emerge, and if it’s a female, will produce pheromones that may attract males from as far as several miles away.

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