. Annual report. Entomological Society of Ontario; Insect pests; Insects. 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,
. Annual report. Entomological Society of Ontario; Insect pests; Insects. 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-knof 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
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectinsects, bookyear1872
