Spray Mixtures to Control Putnam Scale and Bark Beetles on Elms

Ecology of Forest Insects

“…Refer ences to the increase in populations of aphids, scale insects, and mites fol lowing the application of DDT are numerous but for the most part repeat that which has been said before, An especially interesting situation has de veloped on the University of Illinois campus as reported by English & Decker(70). Spraying with DDT to control the leaf hopper, Scaphoideus luteolus…”

“…Phloem necrosis of elm is apparently transmitted only by a single species of leafhopper, Scaphoideus luteolus Van D. (70).…”