136 Noukoun et al.: Effect of Sticky Bands on Cankerworm Abundance and Defoliation in Urban Trees silk strands (Johnson and Lyon 1991). Hundreds or thousands of dangling larvae become a nuisance to pedestrians (Hiratsuka et al. 1995; Eirich 2008; Lyttle 2012). They also land on and damage neigh- boring trees and plants growing beneath host trees (White and Whitham 2000). In many cities, can- kerworms have become frequent or even annual pests, which causes concern for urban tree health. Two methods are available to manage cater- pillar pests and reduce defoliation. The foliage of infested trees can be sprayed with an insecticide, such as Bacillus thuringiensis kurstaki, to kill lar- vae. However, applying insecticide to large trees in densely populated areas is difficult, expensive, and has consequences for non-target organisms and the environment (Cole et al. 1967; Miller 1990; Tobin et al. 2012). Another method, tree band- ing, has been used to manage cankerworms (Brit- ton 1900; La France and Westwood 2006; Eirich 2008) and other lepidopteran pests, such as gypsy moths (Collins and Hood 1920; Blumenthal and Hoover 1986) and winter moths (Otvos and Hunt 1986) that climb tree trunks as larvae or adults. Tree banding entails wrapping a weatherproof material, such as plastic tape, in a narrow band around a tree trunk and then covering the band with a sticky sub- stance to trap flightless female moths before they reach the tree crown to deposit egg masses (Brit- ton 1900). Sticky bands have been made of many materials, including roofing paper, plastic wrap, and duct tape. Generally, cotton batting, fiber- glass insulation, or a similar compressible material is placed underneath the band to fill crevices that would otherwise allow moths to crawl under the band (Otvos and Hunt 1986; Thorpe et al. 1993). Sticky bands have been recommended and used for centuries to try and reduce damage by lepi- dopteran pests (Deane 1797; Riley et al. 1883; Brit- ton 1900; Collins and Hood 1920). Yet, research on their efficacy is inconsistent. Bands effectively cap- ture winter moths, gypsy moths, and cankerworms, and oſten reduce larval abundance in tree canopies, but in most cases do not reduce defoliation (Blumen- thal 1983; Blumenthal and Hoover 1986; Otvos and Hunt 1986; Thorpe et al. 1993; Thorpe and Ridgway 1994; La France and Westwood 2006). One study has investigated the efficacy of bands for cankerworm management and found that larval abundance and defoliation were not different between banded and ©2014 International Society of Arboriculture unbanded trees (La France and Westwood 2006). However, the authors point out that larval abundance was very low, making these estimates unreliable (La France and Westwood 2006). The goal of the present study was to test the efficacy of simple tree bands to reduce larval abundance and defoliation of large oak trees by fall and spring cankerworms. No study has shown a benefit to using compressible crevice- filling material beneath bands. So the authors chose to test bands without compressible material, which would be simpler and less expensive to construct and install. No bands, one band, or two bands were arranged for large willow oaks (Quercus phellos) to determine: 1) the seasonal activity of fall and spring cankerworm adults; and how the number of bands affects 2) the number of moths captured; 3) larval abundance in the canopy; and 4) canopy defoliation. METHODS AND MATERIALS This experiment was conducted on the campus of North Carolina State University in Raleigh, North Carolina, U.S. On October 24, 2012, the study authors selected eleven sites that each con- tained three similar-sized willow oaks. Sites were separated by at least 100 m. Experimental trees at each site were not touching each other or any other tree. Tree DBH was measured and compared among treatments using ANOVA. Trees within each site were randomly assigned to receive zero sticky bands, one sticky band, or two sticky bands, and labeled by the sticky band treatment they received. Willow oaks were chosen as a study species because they were the primary host for cankerworms in previous sea- sons and one of the most common tree species in Raleigh. Each trunk was wrapped at breast height with a 7.6 cm wide band of Tanglefoot Tangle Guard™ (Contech Inc., Victoria, British Columbia, Canada) banding material. The bands were stretched tightly and held in place with sta- ples. Trees in the two-band treatment had bands placed 15 cm apart. Tanglefoot™ (Contech Inc., Victoria, British Columbia, Canada) was applied approximately 5 mm deep with a putty knife to cover the paper bands. Tanglefoot was reapplied as needed when it became thin from scraping off moths or when bands became covered in debris. To determine the seasonal abundance and activity of adult female cankerworms, research-
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