In the last Bulletin we gave the results of an experiment with the hopperdozer or tar pan on a piece of pasture land in increasing the capacity of pasturage. At the same time we were working upon the life histories of the more destructive species of leaf hoppers, and a summary of those results with their economic bearing will be presented here.
Our first effort was to determine the manner in which the winter is passed. Adults of several of the species studied had been observed late in autumn and early winter and even on mild days late in December, so that it was at one time thought they might hibernate and deposit eggs in spring. Careful search, however, in early spring failed to discover any of them except Agallia sanguineolenta, which, as heretofore shown, is mainly a clover insect, and Tettigonia hieroglyphica, which occurs mostly in wooded places. No specimens whatever of the species of Deltocephalus and Diedrocephala, which are the most destructive pasture species, were found. This seemed to show pretty certainly that the eggs were deposited in autumn, and the question next to determine was where they were laid. To determine this point, as well as to secure additional evidence as to the possibility of adults living over winter, a small patch of blue grass sod was enclosed by a tight board set on edge fitting closely into the ground and extending up about two feet so as to make it impossible for any of the leaf hoppers to enter from without. The enclosed patch was carefully examined to make sure that no hoppers, either young or old were present, and it was examined very frequently as well as the outside portions, to determine just when young hoppers appeared. As soon as the larvae appeared in grass land outside they appeared also in this enclosed patch in large numbers, showing we think conclusively that the eggs are deposited in the grass itself and as other observations have shown that they are placed in the blades of grass, there is apparently no reason to doubt that the eggs occur in the dead or withered leaves of grass near the ground through winter and in early spring.
"Grass leaf hoppers,"
Bulletin: Vol. 2
, Article 5.
Available at: https://lib.dr.iastate.edu/bulletin/vol2/iss20/5