Butterflies (Lepidoptera) of young midfield shelterbelts

The study was carried out in 1999–2000 in midfield shelterbelts located in mosaic agricultural landscape near village Turew (West Poland) with the aid of transect method (total length amounted to 4520 m). Five shelterbelts (transect length – 3070 m) have been planted in 1993 and one shelterbelt (transect length – 1450 m) in 1998. All the shelterbelts have been planted on arable land. Twenty seven species of butterflies (imagines) were recorded during the study period. Pieris napi and P.rapae dominated in all shelterbelts. Their dominance in 6–7 years old shelterbelts amounted to 30 and 24%, respectively, while in younger one (1–2 years old) – 34 and 32%. Total mean density of butterflies in older shelterbelts was equal to 91.9 ind. km–1 of transect (width 5 m) – and was about 40% higher than in the younger one. Lower dominance of Aphantopus hyperantus (8%) observed in 6–7 years shelterbelts (when compared to several tens years ones) was most likely caused by small share of grasses and perennial dicotyledons, which are important for this species. The butterflies recorded in shelterbelts may be assigned to four ecological groups: ubiquistic species (7 spp.), species typical for open area (10 spp.), species linked to afforestations (3 spp.) and woodland (7 spp.). In all studied shelterbelts most abundant were ubiquistic species and open areas species (Pieris rapae and P. napi) with no respect to age of shelterbelt. Also some rare species with higher environmental demands were recorded, i.e., Polyommatus amandus and Carterocephalus palaeon, which have not been previously observed in the study area