- In the Kampinos National Park (Poland), which is a UNESCO Biosphere Reserve, 47 caught per unit effort samples of Chrysididae were collected in 2000–2006. The aim of the study was to identify the factors promoting the diversity of this rarely studied group of parasitic wasps.
- A total of 722 specimens belonging to 37 species were recorded, including 18 threatened species and six others recently described as new to the Polish fauna.
- No chrysidids were recorded in forests, instead they were most abundant on fallow land (i.e. in open habitats), of which those located on dry soils were preferred over humid ones, just as by their endogeic (nesting in the ground) hosts. Many chrysidids that are parasites of hypergeic (nesting above the ground) species were significantly associated with old abandoned wooden buildings, where their hosts use holes in wood for nesting.
- In addition to the characteristics of the habitat sampled, its position in the land mosaic also determined the diversity of chrysidids. Their lowest abundance and species diversity were recorded in samples from different types of habitat, all located in a uniform environment (i.e. with few other habitats nearby), which limited the diversity of resources available within the flight ranges of chrysidids and their hosts.
- Our study, thus consistent with the concept that habitat heterogeneity enhances faunal diversity, brings important conclusions for the management of park landscapes: afforestation of open areas (both intentional and resulting from natural succession of plant communities) and removal of old abandoned wooden buildings may limit the land mosaicity and thus faunal diversity.