1. Grasshoppers. When and how does sex arise? Grasshoppers are very serious pest of many crops over much of the world, nematologists of Bureau of Plant Industry have been trying to find means of control; [by N. A. Cobb, G. Steiner, and J. R. Christie]. Bookmark Corporate/Agency Authors: Plant Industry Bureau Publisher: Plant Industry Bureau Date: [1927.] SuDoc number: A 1.33/a:Se 91