Lure specificity, phenology, and damage caused by Epiphyas moths (Lepidoptera: Tortricidae) in Western Australian apple orchards.

Abstract

Multiple Epiphyas species inhabit southwestern Western Australia, including Light Brown Apple Moth (LBAM) Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), a globally significant, polyphagous pest. This study evaluated the efficacy and specificity of lures designed for 3 Epiphyas species: E. postvittana, Epiphyas pulla (Turner), and the undescribed Epiphyas sp. (1) (Common). Additionally, the study sought to determine the presence and distribution of Epiphyas species in 3 significant apple-growing localities. Trapping, together with partial sequencing of the mitochondrial COI gene, found LBAM to be restricted to the Perth Hills and E. pulla, to apple orchards near Manjimup and Pemberton. This geographic disjunction remains unexplained. Epiphyas sp. (1) was not recorded despite using a specifically designed lure. The E. pulla and LBAM traps demonstrated superior efficacy in capturing their target species, while the catch in Epiphyas sp. (1) traps did not significantly differ between the 2. Both E. pulla and LBAM exhibited peak abundance from late spring to the end of summer (October-February), with variations in timing and peak catch of male moths across species, locations, and years. Surveys conducted in April during the harvest period (February-May), when moth traps caught an average of 1-1.8 moths/trap/week, found no Epiphyas larvae or damage on 140,400 mature apples or on 26,000 leaves. While E. pulla and LBAM traps effectively monitor their target moths, genetic identification of trap catch would be necessary if they co-occurred. Encouragingly, the results indicate that both species become relatively rare as harvest season approaches, and neither inflicts significant damage to mature apples under existing management.