April, '11] NORTON: health of plants as related to insects 273 



sprayed with the bacteria, and the destruction of these insects is 

 recommended as a combative measure. 



Rudow holds the infection of Prunus with Exoascus to be favored 

 by the development of the fungus in the sugary secretion of plant lice. 



J. Behrens thinks that insects carry the spores of Nedria cinna- 

 barina. He noted that flies visited the fungus. 



Descours Desacres observed that Nedria ditissinia, associated with 

 the canker of fruit trees in Europe, entered, through the openings 

 made by aphids, the same insect also transmitting the spores from one 

 tree to another. 



Noack observed that Ophionedria coccicola, a fungus living on scale 

 insects in Florida and elsewhere, passed from the insect into the 

 orange twigs and there caused a gummosis. 



In the Sphacelia stage of the ergots a honey-like substance filled 

 with the spores is produced. This is sought by Melanostoma mellina, 

 Rhagonycha fulva and other insects, according to R. Stager, and by 

 them introduced into young grass flowers. 



A disease of sugar cane due to Trichosphaeria studied by Massee, 

 Prilleaux and Delacroix enters through the openings made by a beetle, 

 Xyleborus perforans, the moth borer and the weevil, borer, Sphenophorus 

 sericeus. 



Von Schrenk found that the wound parasite fungus Ceratostomella 

 pilifera, causing the bluing of the wood of Pinus ponderosa entered 

 through the borings of Dendrodonus ponderosce. 



A Cucurhitaria disease of trees is carried by snails that feed upon the 

 stroma of the fungus. 



In discussing the larch canker caused by Dasyscijpha, a strictly 

 wound parasite, Hartig mentions wounds made by Coleophora laricella 

 and Chermes lands as offering an entrance for the fungus. Also 

 Dasyscypha resinaria enters spruce through the work of Chermes 

 abietis. 



The conidia of Sderotinia urnula are carried to the flowers, of Vac- 

 cinium vitis-idcea by insects attracted by their fragrant smell accord- 

 ing to Woronin. The same is true of other sclerotinias. 



The sderotinia of the brown rot of peach, etc., enters chiefly through 

 the punctures of insects [chiefly curculio here]. 



The spores of smuts hke Usiilago violacea which take the place of 

 pollen in the anthers of flowers they attack may be carried from 

 flower to flower by insects just as the pollen is. 



According to von Schrenk the white rot fungus, Fomes juniperinus 

 enters the red cedar through openings made by beetles. 



The Phoma disease of cabbage is said to enter through wounded 

 roots and insects are suspected. Anthomyia brassicoe is mentioned. 



