425 Abundance of Epiphyas postvittana (Walker, 1863) in forestry nurseries of São Miguel Island (Azores, Portugal) (Lepidoptera: Tortricidae) L. Oliveira, V. Vieira, A. O. Soares, I. Borges, P. Arruda & J. Tavares Abstract Epiphyas postvittana (Walker, 1863) is an invasive polyphagous pest for the Azores and its bioecology and the potential natural enemies were unknown. We evaluated the temporal profile of this species larval abundance and the number of males captured in sex pheromone traps, hypothesizing that both profiles were similar. The study was carried out on seven endemic host plants and one native species grown in two forest nurseries (Furnas and Nordeste) in São Miguel Island over two years from 2018 to 2019. A total of 827 plants attacked by E. postvittana were observed in Furnas nursery (2018: 503, 2019: 324) and 1227 in the Nordeste (2018: 649, 2019: 578), including the presence of 525 larvae distributed by the Furnas (2018: 178, 2019: 79) and from the Nordeste (2018: 131, 2019: 137). In 2019, the average weekly number of males captured in the sex pheromone traps (total 31 weeks) were higher in Furnas (mean ± SE: 9.68 ± 1.982) than in Nordeste (3.33 ± 0.651). In synthesis, (i) the population density varied throughout the year and as a function of the host plant species in production; (ii) the abundance profile of larval and adults suggests has at least three to four generations per year and that adults are active year-round, experiencing some delayed development during the winter; (iii) a low larval density does not represent very serious damage to Azorean endemic plants, but is reflected in the population density of its natural enemies; (iv) some biological control agents are present in the field, parasitizing the larvae (i.e., Braconidae species of Meteorus ictericus (Nees, 1811) and Microgaster opheltes Nixon, 1968); (v) finally, the knowledge of the population dynamics and its natural enemies needs further and long-term study. KEYWORDS: Lepidoptera, Tortricidae, Epiphyas postvittana, endemic woody plants, forestry nurseries, Laurel Forest, Azores Islands, Portugal. Abundancia de Epiphyas postvittana (Walker, 1863) en viveros forestales de la isla de São Miguel (Azores, Portugal) (Lepidoptera: Tortricidae) Resumen Epiphyas postvittana (Walker, 1863) es una plaga invasora polífaga en las Azores, pero su bioecología y ene- migos naturales eran desconocidos. Evaluamos el perfil temporal de la abundancia de larvas de esta especie y el nú- mero de machos capturados en trampas de feromonas sexuales, con la hipótesis de que ambos perfiles eran simila- res. El estudio se llevó a cabo en siete plantas nutricias y una nativa cultivadas en dos viveros forestales (Furnas y Nordeste) en la isla de São Miguel durante dos años consecutivos de 2018 a 2019. Se observaron un total de 827 plantas atacadas por E. postvittana en el vivero de Furnas (2018: 503, 2019: 324) y 1.227 en el Nordeste (2018: 649, 2019: 578), incluyendo la presencia de 525 larvas distribuidas por el Furnas (2018: 178, 2019: 79) y del Nordeste (2018: 131, 2019: 137). En 2019, la media semanal de machos capturados en las trampas de feromonas sexuales (to- tal 31 semanas) fue mayor en Furnas (media ± SE: 9,68 ± 1,982) que en Nordeste (3,33 ± 0,651). En síntesis, (i) la SHILAP Revta. lepid., 50 (199) septiembre 2022: 425-433 eISSN: 2340-4078 ISSN: 0300-5267 https://doi.org/10.57065/shilap.56