Malaise-hyönteispyynti Lapin suojelualueilla 2012–2014

During 2012-2014, the Parks {&} Wildlife Finland (Metsähallitus, Lappi) performed biodiversity inventories of insects by using Malaise traps. Malaise traps are suitable for collecting low-flying insects in all habitats. A total of 85 traps were set in 24 conservation areas. The traps were placed on aapamires, springs, alpine wetlands and forested habitats. The average collecting effort was 103 days/trap. The following orders were identified from the traps: hemipterans (Hemiptera), bark lice (Psocoptera), caddisflies (Trichoptera), several true fly families (Diptera) and beetles (Coleoptera). Four thoroughly well-studied insect groups consisting of selected nematoceran families, hemipterans, chironomids and caddisflies, were identified from all sites in all three years. The identified material consisted of ca. 80000 specimens. The observed total number of species was 2011, of which 752 species were singletons (i.e. were identified only from one conservation area). Most of the encountered species were dipterans (1587), other groups yielded 424 species (Hemiptera 184, Coleoptera 122, Trichoptera 86, Psocoptera 29). During the survey, a total of 112 species were found for the first time from Finland. The material included 58 taxa that are still undescribed, that is, they lack a scientific name. Of these undescribed taxa a vast majority were dipterans (57), only one was a caddisfly. A total of 66 nationally red-listed species (DD, NT, VU, EN) were observed. Törmäoja conservation area in Savukoski was the most species rich site (811), but the trapping effort (1113 trapping days) was also the highest there. There was a positive correlation between trapping effort and observed species richness and also between observed species richness and the number of red-listed species. The correlations of species richness between the four thoroughly studied groups were either weakly positive or no correlation was found. According to the Mantel test, assemblage variation of these four groups was concordant. In northern areas the importance of dipterans is relatively high. In the future true flies should be more often used as a target group in biotic inventories. In general, inventories and mappings should include several taxonomic groups, or different guilds or groups that differ in their habitat requirements. The relatively high number of undescribed species indicates how poorly we know assemblages inhabiting conservation areas. This report is also an example of a productive co-operation between the administration (Parks {&} Wildlife Finland) and entomologists.