ORDER COLEOPTERA 



103 



After the larve enters the cocoon it shrinks longitudinally into 

 semiquiescent, compact, prepupal stage, in which it remains 

 until the following spring, when it transforms to a pupa. The 

 prepupal stage is long and lasts almost from the first of August 

 until the following May. By the first week in September the 

 cocoon with the dried leaf tissue over it somewhat resembles a 

 Desmodium seed in color and shape. Later the leaves containing 

 the cocoons and in fact all of the leaves fall to the ground and here 

 the prepupa passes the winter. 



UD 



Fig. 60. Leaves of Desmodium with mines of Pachyschelus laevigatus. 

 (From Weiss and West.) 



Taphrocerus 



One species, T. gracilis, has been carefully studied and 

 reported upon by Chapman (1923). We borrow one of 

 his figures, and abstract a portion of his account of its habits. 



Its host plant is the flood-plain bulrush, Scirpus fluviatilis. 

 About the end of June the eggs are laid singly on the surface 

 of the fully developed leaves, almost anywhere from base to 

 tip on either side but generally about midw T ay between the 

 midrib and a leaf margin. They are soft and translucent 

 when laid. They flatten out on the leaf like a viscid drop- 



