Siberian, Elm Leaf Beetle Control, 1978

Native Siberian elms, approximately 15 feet in height located 8 miles east of Still-water, Oklahoma were selected for the test. Trees were treated on Jun7 when larval populations increased to economic levels. Larvae were 1/8 to 3/8 inch in length. Application equipment consisted of a John Bean 55 sprayer series L-1565-2 and a 785 John Bean Spraymaster deluxe gun which delivered 1.76 gal/min of finished spray at 300 psi . Trees were treated until runoff. Treatments were randomized and replicated five times along with a check. Larval counts were made by examining 18" of terminal branch at six locations per replicate.