448 EXPERIMENT STATION EECOED. 



Notes on some diseases of trees in our National Forests, V, G. G. Hedgcock 

 (Phytopathology, 5 {1915), No. 3, pp. 175-181) .—In continuation of notes on for- 

 est tree diseases (E. S. R., 31, p. 845), the author describes the attacks and 

 distribution of Razoumofskya and Phoradendron on different species of forest 

 trees. 



Insects as carriers of the chestnut blight fungus, R. A. Stxidhai-teb and 

 A. G. RuGGLEs {Penn. Dept. Forestry Bui. 12 {1915), pp. 38, pis. //).— This is a 

 detailed account of the investigations carried on jointly by the Office of Forest 

 Pathology of the Bureau of Plant Industry of this Department and the Penn- 

 sylvania Chestnut Tree Blight Commission, a preliminary report of which has 

 already been noted (E. S. R., 31, p. 451). 



In addition to the previous account, the authors state that 19 out of 52 insects, 

 representing the orders Hemiptera, Coleoptera, Diptera, and Hymenoptera, were 

 found carrying the spores. From the development of the colonies in cultures 

 it appeared that insects from the field were carrying pycnospores almost ex- 

 clusively. 



A bibliography is given. 



A honeycomb heart rot of oaks caused by Stereum subpileatum, W. H. 

 Long {I'. K. Dcpt. Ayr., Jour. Ayr. Research, 5 (1915), No. 10, pp. !,21-Jt2S. pi. 

 1). — In a previous publication (E. S. R., 30, p. 52), the author described some 

 fungi causing rots of oaks in different parts of the United States. In the 

 present paper, an account is given of a rot to which the name honeycomb heart 

 rot is given, due to /S. subpileatum, which is said to be similar to but di.stinct 

 from the rot caused by S. frustulosutn. 



Fourteen or more .species of Quercus and possilily IJquidamhar styraciflua 

 are known to be attacked by this fungus, which is rather widely distributed, 

 as indicated by the collections examined. Trees of all ages seem to be subject 

 to the attack if they are old enough to have formed heartwood. 



The only method of control seems to be prevention of infection. This can 

 be done by eliminating forest fires, which cause wounds on the tree, and pre- 

 venting the formation of the. fruiting bodies of the fungus. As the fungus 

 continues to grow in a tree after it is felled, all cull logs and tree tops should 

 be destroyed to prevent the formation of sporophores. 



A new scarlet oak disease, D. C. Babcock (Phytopathology, 5 {1915), No. 3, 

 p. 197). — A brief note is given on a serious killing of young branches of .scarlet 

 oak in the vicinity of (Mncinnati. which is believed to be due to attacks of a 

 species of Botryodiplodia. 



A new Macrophoma on galls of Populus trichocai'pa. E. E. HrBEUT {Phyto- 

 pathology, 5 (1915), No. .'?. pp. 1S2-1S5, figs. .3).— In the fall of 1009. a collection 

 of galls occurring on /'. trichocarpa was made on the supposition that they 

 were caused by an insect. Upon examination, there was no evidence of insect 

 origin. Later other collections were made for study, and the trouble was found 

 to be due to a fungus which is described by C. L. Shear as 1/. tumcfacicns n. .sp. 



The galls, with the accompanying fungus, are said to have been widely dis- 

 tributed in Montana, a number of collections having been made in that State 

 and in Idaho. 



Pink disease of plantation rubber, F. T. Brooks and A. Sii akpi.es (.1h». 

 Appl. Biol., 2 {1915), No. 1, pp. 5S-S0, pis. 2, figs, ii).— Work previously reix)rted 

 (E. S. R., 33, p. 151) has been followed up with more detailed investigation, 

 and the chief results thereof are given. 



The distribution, hosts, and mode of action of pink disease are discussed, as 

 are the forms of the causal organism {Corticium salmonicolor) , its action on 

 the wood being de.scribed in detail. The formation of tyloses is considered as 

 a response to the presence of the fungus in the wood. I'ure cultures of the 



