114 Bulletin of the Brooklyn Entomological Society Vol. XI 



LIVING PUPAE FOR SALE. 



For many years it has been the custom of a few of us to dis- 

 tribute among schools, etc., a large number of cocoons of Satur- 

 niids for study purposes. Now, for the benefit of our publica- 

 tion fund and in the interest of science we offer : 



Sound cecropia cocoons $i.oo per loo 



Parasitized or dead cocoons 25 



Best cynthia cocoons i.oo 



Dead ones, generally bacterial 25 



Our best selection of promethea i.oo 



On all orders from 50 cents upward postage will be prepaid. 

 On lesser orders kindly add fair postage. We shall give our time 

 in safe packing, etc. 



When the late John B. Smith worked upon the parasites and 

 diseases of cecropia, we collected for him about 19,000 cocoons. 

 In this species we can detect living or dead. The latter may be 

 of interest either for silk or diseases. The parasites are gen- 

 erally a Pimpla or a large Ophion. Cecropia can be bred on 

 almost any deciduous tree in any climate. It is to be hoped that 

 much more will be done in efforts at hybridization. 



From the cynthia cocoons come the pongee silk of commerce. 

 This insect was first introduced from China to Brooklyn about 

 1867. It feeds normally upon the Ailanthus tree. It has been 

 bred ex ovo on species of oak. If bred on wild cherry the 

 imagines are distinctly dwarfed. Sassafras has been success- 

 fully used. Other trees should be tried. The silk value of this 

 species is great. Hybridization has been carried on extensively. 

 Recorded successes are with promethea (both sexes), cecropia, 

 Columbia, gloveri, calif ornica. Its parasites are not numerous. 

 We believe there is a good field so that biologists should experi- 

 ment on not fewer than 50,000 cocoons this coming season. 



Cocoons of promethea are getting scarce around New York. 

 Where we used to find hundreds on wild cherry, almost any tree 

 in a grove, we now find dozens on trees widely scattered. The 

 parasites are several and interesting. They respond readily to 

 attempts at hybridization. Food trees are many in any climate. 

 The silk is tough and of excellent quality. 



