296 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 1 



mens in the Brehme lot were not counted, it means that less than 

 twenty-five per cent of the total number matured, and that was not 

 because of any hyperparasitism, but a simple failure of the larva to 

 make a proper pupa. This experience by the by, is not a new one to 

 me. In years past I have cut Opliion cocoons in large numbers, find- 

 ing sound larvae and pupae as exceptions only and a putrid brown 

 semi-li(juid mass as the rule. Mr. Grossbeck informs me that he has 

 never foimd anything l)ut the same pasty mass, and therefore it 

 seems that this parasite is kept in check by some disease that reaches 

 it within the body of its host. 



Assuming that there were actually eighty Ophion parasites, that 

 left remaining 215 cecropia cocoons containing massed Ichneumonid 

 cocoons. The number of individuals in these masses was not deter- 

 mined, but there were certainly more than ten, which would make an 

 expectation of 2,000 parasite examples a very moderate one. Instead 

 of that we bred out, Spilocryptus extremis, 124- specimens, Spilochal- 

 cis mariae, 51 specimens; a total of 176 examples instead of the ex- 

 pected 2.000. 



But we were not left without specimens for count, because we bred 

 out over 48,000 examples of Dibrachys houcheanus or some very closely 

 allied form. The species was referred through Dr. L. O. Howard to 

 ]\Ir. J. C. Crawford, and the determination was received as above, with 

 the statement that this was a hyperparasite on Ichneumonida?. Mr. 

 Grossbeck actually counted 33,000 of the little specimens and esti- 

 mated the balance; conservatively, I am certain, for I myself believe 

 that the total was nearer to 50,000 examples. Assuming that the 17G 

 Spilocryptus and Spilochalcis were the product of fifteen cocoons, 

 that left the nearly 50,000 examples to emerge from 200 cocoons, or 

 250 examples from each cocoon; twenty-five h.\ peiparasites from every 

 true parasite. 



Actually there were over 280 hyperparasites to every primary para- 

 site and this would seem to afford a very decent check to undue in- 

 crease, so as to prevent the complete extermination of cecropia by 

 parasites alone. 



This series of notes is published at this time as a suggestion to some 

 of our younger investigators. An extremely valuable set of data can 

 be secured by collecting in some limited locality all the cocoons of 

 some of our large Bomhycids, sorting them so as to separate sound 

 from dead or parasitized forms and sorting the latter so as to sep- 

 arate the different kinds of parasites so far as these may be deter- 

 mined without interfering with their development. Collections should 

 be made in late fall and in late spring to determine the influence of 



