INSECTS AND HUMAN WELFARE — DUNCAN 347 



REFERENCES 



(1) CnAMIiEHLIN, W. J. 



1939. The b.'irk and timber beetles of North America. Oregon State Col- 

 lege Cooperative Association, Corvallis, Oreg. 



(2) Ckaiohead, F. C. 



1930. An annotated list of the important North American forest insects. 



U. S. Dep. Agr. Misc. Publ. No. 74. 



(3) DoANE, R. W., Van Dyke, E. C, Chambeblin, W. J., and Burke, H. E. 



1936. Forest insects. McGraw-Hill Booli Company. 



(4) DoDD, Allan P. 



1940. The biological campaign against prickly pears. Coommonwealth 

 Prickly-Pear Board, Brisbane, Queensland, Australia. 



(5) FoLSOM, J. Vv'., and Wardle, K. A. 



1934. Entomology with special reference to its ecological aspects. Mc- 

 Graw-Hill Book Co. 



(6) Graham, Samuel Alexander. 



1939. Principles of forest entomology. McGraw-Hill Book Co. 



(7) KxiOHT, Paul. 



1939. The problems of insect study. 2d ed. Edwards Bros. 



(8) LuTz, F. E. 



1931. In defense of insects. Sci. Month., April. 



(9) Metcalf, C. L., and Flint, W. P. 



1928. Destructive and useful insects. McGraw-Hill Book Co. 

 (10) Wheeler, William M. 



1926. Ants. Their structure, development and behavior. Columbia Uni- 

 versity Pre.ss. 



