June, ’24] 
johannsen: apple tree borer control 
383 
farm practice. Separate from Scientific Monthly, June, 1919, pp. 496-513, 
3 figs. 
- 1920. The bioclimatic law. Jour. Washington Acad. Sci., Washington, 
D. C., Vol. io, No. 2, pp. 34-40. 
--— 1921. Intercontinental problems in bioclimatics, with special reference 
to natural and artificial distribution of plants and animals. Jour. Wash. 
Acad Sci., 11 (1921) No. 10, pp. 223-227. 
-1921. Bioclimatic zones determined by meteorological datz. U. S. 
Monthly Weather Review 49 No. 5, pp. 299-300. 
- 1921. Bioclimatic zones of continents, with proposed designations and 
classification. Journal Washington Acad, of Science, Vol. XI, No. 10, pp. 
227-229. 
Knoche, 1908. Uber Borkenkaferbiologie und Borkenkafervertilung. Forstwiss 
Zentralblatt, XXX. 
MacDougal, D. T., and Working, E. B., 1921. Another high temperature record 
for growth and endurance. Science, n. ser., 54, No. 1390, pp. 152, 153. 
Merriam, C. H., 1894. Laws of temperature control and geographic distribution of 
terrestrial animals and plants. Nat. Geographic Magazine, VI, 228-238. 
Peairs, L. M., 1915. The relation of temperature to insect development. Jour. 
Econ. Ent. y.T74-183. 
Pierce, W. D., 1916. A new interpretation of the relationships of temperature and 
humidity to insect development. Jour. Agr. Res. Vol. 5 , No. 25, pp. 1183- 
1191. 
Sanderson, E. Dwight, 1908. The influence of minimum temperature in limiting 
the northern distribution of insects. Jour. Econ. Ent. 1 : 245-262. 
-1910. The relation of temperature to the growth of insects. Jour., 
Econ. Ent. Vol. 3, No. 2, pp. 113-140. 
-, and Peairs, L. M., 1913. The relation of temperature to insect life. 
N. H. College of Agr. Exp. Sta. Tech. Bui. 7. 
Summers, T. N., 1922. Effect of low temperature on the hatching of gipsy moth eggs. 
U. S. Dept. Agr. Bui. 1080, pp. 14. 
Swaine, J. M., 1908. Canadian barkbeetles, Part II. Bui. 14, Part II, Ent. Branch 
Dept, of Agr., Ottawa. 
A METHOD FOR THE EXTERMINATION OF THE ROUND- 
HEADED APPLE-TREE BORER 
By O. A. Johannsen, Ithaca, N. Y. 
Abstract 
As a substitute for the “digging-out” process, fumigation with carbon disulphid 
proved very successful. Against the tree, with the open side over the borer holes, a 
cell with open top, resembling a large mud wasp’s nest, is built of plastic clay or mud. 
A teaspoonful of carbon disulphid is poured in and the cell closed with a plug of clay. 
The surface of the cell is then wetted and smoothed down, and carefully sealed to 
the tree and the earth. This method gives 100% control when properly done, re¬ 
quires less time than the “digging-out” process, and neither mutilates nor injures 
the tree. 
