ENTOMOLOGICAL SOCIETY OF ONTARIO. 



25 



The subject of entomogenous fungi is too large to enter on here, but it may be of 

 interest to show specimens of a few of those most commonly ^met with. 



The first is a parasite on the scale insect (Lecanium sp.), which I find on oak, ash, 

 and blue beech. It is called Cordyceps clavulata (Schw) ; the genus is in the same order 

 with the medicinal ergot or smut of rye. The fungus feeds upon the tissue of the insect, 

 •displacing the latter by its vegetative portion. It matures by producing erect sporo- 

 phores, ^ to ^ inch long, bearing papillate conical heads. Under each papilla is em- 

 bedded a perithecium containing numerous sacs or pods called asci, each of these sacs 

 •contains eight long, separate sporidia or " seeds." 



Fig. 9. 



Fisr. 12. 



Fig. 13. 



Fig. 9. — Twig with two scale insects. One of them killed by Cortyceps clavulata, having three sporo 

 phores of the fungus. 



Fig. 10. — Head of one of the sporophores enlarged. 



Fig. 11. — Cross-section of head of sporophore showing the flask -like psrithecia greatly enlarged. These 

 perithecia are filled with sacs as indicated at a. 



Fig. 12.— A sac or ascus containing eight sporidia still more highly enlarged. 



Fig. 13. — A sporidium or " seed " magnified 750 diameters. 



The fly-fungus, Bmpusa muscce, Cohn, belongs to a very different group of fungi. 

 The former is placed in the class with black-kno f of the plum tree and the mould on the 

 gooseberry. This has close rplationship to the white mildew of the grape, to the peron- 

 ospora which produces soft rot of the potato, and to that causing a peculiar 

 stinking decomposition of fish. No doubt you have observed dead flies surrounded by 

 a whitish halo adhering to a pane of glass. Tim halo consists of the spores, conidia — 

 and secondary spores thrown off by the growing fungus from the body of the infected fly 



When one of these living spores gets attached to the under side of a fly's abdomen, 

 it puts out a tube which penetrates the skin and rapidly spreads through the whole body 

 in the manner in which yeast grows through bread, feeding upon the fatty substances 

 within the fly. The exhausted fly finally settles, it may be on a pane of glass, there the 

 fungus by abjunction scatters its spores around the body producing that smoky halo to 

 which I referred. 



Dr. Roland Thaxter in his masterly monograph on the Entomophthoreae in which he 

 ■describes the various known species which affect flies, mosquitoes, gnats, aphides, cicadse, 

 thrips and lepidopterse, says ot the house-fly fungus that its occurrence out of doors is an 

 exceptional phenomenon, and that he knew of only two instances. His observation 

 makes the specimens I have laid on the table the more interesting, as they were collected 



