It has frequently been stated by scientific investigators that insects are necessary to convey the pollen in cross fertilization of red clover. The opinion is often expressed by clover growers and some popular writers that insects are not necessary to secure pollination of red clover. The following by Henry Wallace is a fair statement of the position taken by quite a number of agricultural writers.
Proceedings of the Iowa Academy of Science
©1911 Iowa Academy of Science, Inc.
Pammel, L. H. and King, Charlotte M.
"Pollination of Clover,"
Proceedings of the Iowa Academy of Science, 18(1), 35-45.
Available at: https://scholarworks.uni.edu/pias/vol18/iss1/10