Since most of the rather large number of species of May beetles appearing throughout the middle west seem to have a three year life cycle with a greater or smaller number of individuals appearing each year, the resulting three broods have been designated A, B and C. Brood A, which last appeared as destructive grubs in 1927, is the largest brood and causes heavy damage in many sections of the United States. The damage from the grubs of Brood A seems to have been increasing in Iowa in recent years.
Proceedings of the Iowa Academy of Science
©1929 Iowa Academy of Science, Inc.
Jaques, H. E.
"Distribution of Brood B of White Grubs in Iowa in 1928,"
Proceedings of the Iowa Academy of Science, 36(1), 371-371.
Available at: https://scholarworks.uni.edu/pias/vol36/iss1/115