88 ENTOMOLOGICAL SOCIETY OF ONTARIO. 



without discrimination from the trunks of trees in the United States Department of 

 Agriculture paik. From these 624 cocoons issued the following parasites : 



Specimens. 



Pimpla inquisitor 729 



Bathythrix pimpla? 13 



Limneria valida 1 



Theronia fulvescens 1 



Chalcis ovata 69 



Dibrachys boucheanus 50 



Asecodes albitarsis 1 



Frontina aletise 7 



Frontina Frenchii 14 



Tachina mella 12 



Euphorocera claripennis 15 



Exorista griseomicans 4 



Total 916 



The part played by dipterous parasites up to the winter of lfc>96, when the bulletin 

 in question was published, had not been great, only 187 specimens in all having been 

 reaied. All the species were well-known Tachina flies of wide distribution and general 

 parasitism. 



A recuperation in numbers of the Orgyia was quite marked in the spring of 1897, 

 and additional and heretofore unreported observations were made. So great had been 

 the destruction of Pimpla inquisitor that in these observations this species did not 

 appear in a single instance ! Another hymenopterous parasite, Chalcis ovata, became 

 prominent, and it is worthy of note that while secondary parasites of this species are 

 strongly suspected, it is not absolutely known to have any, A striking feature, however, 

 was the great increase in the number of the dipterous parasites'. The rearings were 

 conducted on a large scale, and the following table affords an interesting comparison to 

 the one just given. 



Five thousand larvae and pupa? of Orgyia lexcostigma were collected July 6 to 9, 

 1897. From these there had issued up to August 2 the following parasites : 



Specimen?. 



Tachina mella 220 



Frontina Frenchii 355 



Euphorocera claripennis , 464 



Exorista sp 13 



Helicobia helicis 4 



Phorocera sp 45 



Chalcis ovata 551 



Apanteles parorgyiae 3 



Dibrachys boucheanus 10 



Total 1,665 



Of these it will be noticed that more than two-thirds (1,101) were dipterous, while 

 the previous summer dipterous parasites had constituted only about one-twentieth of the 

 number reared. 



From the 5,000 cocoons there issued also 321 male moths and 764 female moths; 

 146 of the caterpillars or chrysalids died from a disease which we have for convenience 

 called "black rot," and 33 from another disease which for the same reason we have called 

 " red roc," 



