October, '08] JOURNAL OF ECONOMIC ENTOMOLOGY 295 



pupal stage and died. Of these some had masses of white, fungous- 

 like material with a surface coating of orange powder exuding between 

 the segments. Others were drying up and shrivelling; a few con- 

 tained a putrifying mass of yellowish material. Of the remainder, 

 213 were dead as larva? and of these fifty-four had made light or im- 

 perfect cocoons. One hundred and fifty-two were parasitized, and of 

 these twenty had Opliion cocoons, the remainder seeming to be Ichneu- 

 monids of some kind. 



In the lot collected in 1908, eleven cocoons were found to contain 

 sound pupffi and from one the adult had emerged. Thirteen had died 

 in the pupal stage, leaving 305 that had died without pupating. Of 

 these 204 were killed by disease, sixty-one of them making light co- 

 coons, while 101, or less than half as many, were parasitized. Of 

 those that were parasitized, fifty-six contained pupa? of Opliion, while 

 forty-five only went to other species. 



This little examination is interesting because it calls attention to 

 the relative importance of control factors other than parasites. It 

 gives the results from a lot of 1062 specimens and shows that 697, or 

 more than 65 per cent, were killed by disease in either the larval or 

 pupal stage. 



I am quite aware that the statistics are incomplete and imperfect, 

 since the collections were not made of all the cocoons in a given 

 region ; but as they go, they emphasize the importance of a study of 

 the subject from a new standpoint. 



Stated in compact form the results of the study are as follows : 



Total number of cocoons examined 1062 



Sound specimens 36 



Adults had emerged 34 



Died as pupa^ 47 



Parasitized 295 



Dead from disease 650 1062 



The above results were secured by early summer and were com- 

 municated to the Brooklyn Entomological Society at its June meeting. 

 At that time it was announced that the parasites had begun to make 

 their appearance and that the cocoons would be preserved until the 

 record was complete and nothing further issued. 



To all appearance there were two kinds of parasites, the Ophion 

 macrurum, which was of course readily recognizable, and an Ich- 

 neumonid form, making its cocoons in a solid mass in the lumen of 

 the cecropia cocoons. There were seventy-six counted Ophion pupie 

 and from these nineteen adults were obtained. As the Ophion speci 



