Several years' records of dates on which the eggs of this insect hatched at Ames, Iowa.
Proceedings of the Iowa Academy of Science
©1924 Iowa Academy of Science, Inc.
Webster, R. L.
"Notes on the Oyster-Shell Scale, Lepidosaphes ulmi, Linn,"
Proceedings of the Iowa Academy of Science, 31(1), 418-418.
Available at: https://scholarworks.uni.edu/pias/vol31/iss1/145