Control of Elm Leaf Beetles on Siberian Elm, 1982

The test was conducted on a windbreak planting of Siberian elmjj, approximately 20 ft tall, located 2 mi south of Stillwater, Oklahoma. Trees were treated on Jul 26 when the temperature was 92 F and the wind velocity was 5-10 mph. A majority of the larvae were in 2nd and 3rd instar, approximately 8-12 mm long. Application equipment consisted of a Marco R-20 sprayer which delivered 1.6 gal/min at 200 psi. Trees were treated to run-off. Treatments were randomized and replicated 3 times. Larval counts were made by examining 18 in of terminal branch at 10 locations per tree.