Inventering av insekter i Benestads backar och Hagestad naturreservat

The two nature reserves Benestads backar and Hagestad in Scania, southernmost Sweden, were surveyed for insect diversity during 2011 and 2012. Because current management plans for both reserves include a size expansion to increase the protective status also of adjacent areas, the aim of this survey was to derive a measure of current insect diversity in both reserves. These estimates can then be used for comparison in subsequent surveys to estimate how practical conservation efforts are translated into changes in biodiversity. For each reserve we identified a number of insect groups, the diversity of which would best describe the overall quality and current conservation status of each area. For Benestads backar, we surveyed three diptera families; soldier flies, marsh flies and hover flies. Diptera families surveyed in Hagestad were robber flies, hover flies and tachinid flies. In both reserves, we also surveyed all occurring families of Coleoptera and Hemiptera. In addition, for both reserves we surveyed solitary bees caught in bowl traps and a few other aculeata taxa. Practical surveying methods included manual searches and sweep netting, in combination with passive collection using color bowls and pitfall traps. In Benestads backar, we found 432 insect species in all focal groups combined, of which 20 are included on the national IUCN red list. One species, the marsh fly Psacadina vittigera was recorded for the first time from the Nordic countries and two species, the straight-snouted weevil Apion cineraceum and the sphecid wasp Mimumesa beaumonti were recorded for the first time from the province of Scania. The survey of the larger Hagestad revealed 630 species from the focal groups, of which 18 are included on the national red list. Benestads backar contains both thermophilic species that occur exclusively on dry meadows with calcareous soils, and species bound to wet or damp habitats with or without calcareous substrates. The large number of monophagous plant-associated insects in the Benestads backar reserve is also noteworthy. The Hagestad reserve contains areas of utmost insect conservation concern, such as warm, sheltered sand dunes dominated by large areas of exposed sand, dry sandy soils and pristine heathlands. In addition, the Hagestad reserve includes a large grazed area on dry and sandy soils, with an adjacent marsh area with high plant diversity and a correspondingly high diversity of rare species or species that are of conservation concern for other reasons. This report describes insect life and diversity in both reserves with comments on red listed, or otherwise interesting or rare, species, identifies areas of particular conservation concern in the reserves and gives general recommendations for the management of these areas. [100 pp., In Swedish