336 Handbook of Nature-Study 



THE PROMETHEA 



Teacher's Story 



HE promethea is not so large as the cecropia, 

 although the female resembles the latter some- 

 what. It is the most common of all our giant 

 silk-worms. Its caterpillars feed upon wild 

 cherry, lilac, ash, sassafras, buttonwood and 

 many other forest trees. 



During the winter, leaves may often be seen 

 hanging straight down from the branches of 

 wild cherry, lilac and ash. If these leaves are 

 examined, they will be found to be wrapped 

 around a silken case containing the pupa of the 

 promethea. It is certainly a canny insect 

 which hides itself during the winter in so good 

 a disguise, that only the very wisest of birds 



ever suspect its presence. When the promethea caterpillar begins to 

 spin, it selects a leaf and covers the upper side with silk, then it covers the 

 petiole with silk, fastening it with a strong band to the twig, so that not 

 even most violent winter winds will be able to tear it off. Then it draws 

 the two edges of the leaf about itself like a cloak as far as it will reach, and 

 inside this folded leaf it makes its cocoon, which always has an opening in 

 the shape of a conical valve at the upper end, through which the moth 



Promethea cocoons. 



Note how the leaves are fastened by silk to the twigs. 

 Photo by M. V. Slingerland. 



