Willow Leaf Beetle Control on Sandbar Willow, 1989

Sandbar willow trunks planted into the bank of a stream approximately 5 miles northwest of Chillicothe, 111. were sprayed with M-One insecticide on 17 May. The trunks had been planted in the bank during the previous winter to provide erosion control and had tufts of expanding leaves sprouting along the trunks. Tufts of leaves were sprayed with M-One and water or just water (control), 12 tufts each, with a 3-gal hand-pressurized portable sprayer to the point of runoff. The number of leaves/tuft ranged from 8-22. Unhatched eggs were removed on 17 May to preclude additional larval hatch during the test period. Larval length ranged from 1-2 mm on 17 May and 4-7 mm on 23 May. A leaf was considered damaged if at least 50% of the leaf suffered larval feeding damage. The number of damaged and undamaged leaves/shoot was recorded on both 17 May and 23 May. This was converted to % increase of damaged leaves/shoot during the test period.