The biodiversity of agricultural land is usually measured via indicator species that can be recorded time- and cost-efficiently. Behind this approach lies the seldom-questioned assumption that these groups of organisms are good at reflecting the overall species diversity of a habitat. We tested this assumption by comparing the diversity of cow-dung insects with that of grasshopper, butterfly, vascular plant and nearby moss and snail communities on 24 pastures on the Swiss Central Plateau. The diversity of the vascular plants and mosses increased with that of the (often herbivorous) butterflies, grasshoppers and snails, both on the sites examined in our study and on those in the wider vicinity. By contrast, the diversity of the dung insects (flies and parasitic wasps) did not correlate with other groups of organisms. Consequently, vascular plants, grasshoppers, butterflies, mosses and snails can represent one another well. This is not, however, the case for dung insects: they, and hence most likely their functions in decomposing dung, are scarcely represented by the commonly used indicators.
Biodiversity of cow-dung insects and other pasture dwellers not correlated