Heim.
1898. The Biologic Relations Between Plants and Ants. Smithsonian Report for 1896, pp. 411-455.
Hopkins, A. D.
1909. Insect Depredations in North American Forests and Practical Methods of Prevention and Control. U. S. Dept. Agr., Bur. Ent., Bull. No. 58, pp. 57-101.
Contains many facts of much ecological value showing the interrelations existing between forests and insects. Good examples of insects as initiators of successions and changes in insect associations.
Hubbard, H. G.
1897. The Ambrosia Beetles of the United States. U. S. Dept. Agr., Div. Ent., Bull. No. 7, N. S., pp. 9-30.
The relations of bark beetles to fungi.
Huber, J.
1907. The Founding of Colonies by Atta Sexdens. Smithsonian Report for 1906, pp. 355-372.