Species composition and flight periods of horntail wasps (Hymenoptera: Siricidae) within Basque Country pine forests, with the confirmation of establishment of the exotic species Urocerus albicornis

Abstract

Species composition and flight periods of horntails wasps in Basque Country pine forests in northern Spain are studied in order to determine if alien invasive species have been introduced and established. Panel traps baited with Contech Inc. Sirex noctilio lures were erected at sites in six distinct Basque Country forest regions (Menagarai and Gordoa forests in Alava Province, Orio and Zegama forests in Gipuzkoa province and Carranza and Muxika forests in Bizkaia province). Traps were monitored throughout 2011 and 2012. At the same time in January, ten dead logs with oviposition holes from the same localities were collected and reared in emergence cages for wasp collection. In the pheromone traps three autochthonous, Palaearctic species were found: Sirex noctilio Fabricius, 1773, and Urocerus gigas (Linnaeus, 1758), and one exotic species Urocerus albicornis (Fabricius, 1781) was detected. From logs, the same three species plus U. augur (Klug, 1803) were obtained with a collection of parasitoids. Sirex noctilio, Urocerus gigas and Urocerus albicornis were found in all provinces of the Basque Country. Trapping results show flight occurs from late June to September. The establishment of U. albicornis, an exotic species from North America, is confirmed in northern Spain.