SPECIES RICHNESS AND DISTRIBUTION OF BUTTERFLIES (LEPIDOPTERA, HESPERIOIDEA, PAPILIONOIDEA) IN AN AGRICULTURAL ENVIRONMENT IN SE FINLAND

A five-year follow-up study was carried out to assess the species rich ness, adult flight period and distribution of butterflies in an agricu ltural environment in southeastern Finland in the years 1991-1995. But terflies were monitored once a week from early May to late September o n a 2.5-km field boundary transect. During 107 counts, a total of 49 s pecies and 6112 individuals were observed. More than half of all indiv iduals (56%) were observed in July. The results of multivariate analys es indicated that the occurrence of species was related to three habit at types, classified as field margins dividing arable field and conife rous forest, arable field and deciduous forest and two arable fields. Species richness was higher in field margins near forests than in marg ins between two fields.