19141 
VON SCHRENK—A TRUNK DISEASE OF LILAC 259 
or brushing the lower parts of trunks with whale oil soap, or its 
equivalent, should also prove of value. Wherever a diseased 
trunk is found it should at once be cut out and burned. All 
dead wood in the neighborhood of lilac bushes should be cleaned 
up, so that the chances for infection may be reduced. 
LITERATURE CITED 
1. Beutenmüller, Wm. Monograph of the Sesiide. Mem. Am. Mus. Nat. Hist. 
1:244. 1903. 
2. Felt, E. P. Insects affecting park and woodland trees. Rep. N. Y. State Mus. 
59:: 8-332. 1905. [cf. p. 104.) 
[For other insects attacking lilac see Rep. М. Y. State Mus. 59%: 839. 1905.) 
3. Klebahn, Н. Krankheiten des Flieders 1-60. Berlin. 1909. [Шивё.] 
4. Minch, Ernst. Untersuchungen über Immunität und Krankheitsempfánglichkeit 
der Holzpflanzen. Naturwiss. Zeitschr. f. Forst u. Landw. 7:54-75, 
87-114, 129-60. 1909. 
5. von Schrenk, Hermann. The diseases of the hardy catalpa. U.S. Dept. Agr., 
Bur. Forestry Bul. 37:51-58. 1902. 
6. ——————, A disease of white ash. U.S. Dept. Agr., Bur. Pl. Ind. Bul. 32: 1-20. 
1908. [ef. p. 14.) 
