Sampling strategies and density–defoliation relationships for the pale-winged gray moth, Iridopsis ephyraria, on mature eastern hemlock

• Published in: Forest ecology and management Vol. 255; no. 7; pp. 2829 - 2834
• Main Authors: Pinault, Lauren L., Quiring, Dan T.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 20.04.2008; [Amsterdam]: Elsevier Science; Elsevier
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; beeting sheets; Biological and medical sciences; defoliation; density; Density–defoliation; forest trees; Fundamental and applied biological sciences. Psychology; Hemlock; insect pests; instars; Iridopsis; larvae; Lepidoptera; methodology; Monitoring; moths; ova; ovitraps; phytophagous insects; plant pests; Sampling; sticky tape; Synecology; Terrestrial ecosystems; Tsuga canadensis; Nova Scotia; Sampling; Monitoring; Lepidoptera; Hemlock; Density–defoliation; Density-defoliation; Insecta; Sampling design; Density; Tsuga canadensis; Defoliation; Surveillance; Arthropoda; Gymnospermae; Coniferales; Spermatophyta; Invertebrata; Maturity
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2008.01.058

The pale-winged gray moth, Iridopsis ephyraria (Walker), a native geometrid moth species found across eastern North America, has recently caused severe defoliation of eastern hemlock trees, Tsuga canadensis (L.) Carrière, in south-central Nova Scotia, Canada. Field studies were carried out to develop sampling techniques that could be used to predict subsequent defoliation of mature hemlocks, which are too large to sample by conventional methods. Densities of newly emerged, first-instar larvae, estimated by sticky tape traps, explained 77% of the subsequent current-year shoot defoliation by I. ephyraria. Egg densities from foam oviposition traps and mid-instar larval densities from beating sheets were weakly and usually non-significantly related to defoliation. Therefore, foam oviposition traps could be used to qualitatively estimate egg densities of I. ephyraria, but first-instar larvae must be sampled with sticky tape if accurate predictions of hemlock defoliation are desired.