The orthopterans of the rice agroecosystem in western Lomellina (Lombardy, Italy)

Abstract. Rice fields represent a valuable surrogate habitat for many wetland species, playing an important role for biodiversity conservation in human-managed landscapes. Despite the fact that several taxonomic groups have been thoroughly investigated in this agroecosystem, little is known about the orthopteran fauna which lives in and around rice paddies, especially in Europe. In this paper, we provide a first description of the orthopteran assemblages hosted in the rice agroecosystems of northern Italy, trying to evaluate their conservation value through an analysis of species ecological traits (habitat specificity and dispersal capacity). During field samplings in summer 2016, we detected 25 orthopteran species. The 24% of the community was composed by habitat specialist species and the 56% of the sampled taxa was characterised by high dispersal capacities. Rice fields are an extremely dynamic ecosystem, characterised by the continuous succession of flooding and drying periods and conditioned by many other farming activities. Consequently, the orthopteran fauna in rice crops is mainly composed of species well adapted to sudden environmental changes. On the other hand, rice fields represent a particular biotope, providing a suitable habitat especially for hygrophilous species, which are otherwise restricted to scattered marsh areas. In order to preserve orthopteran diversity in rice agroecosystems, sustainable farming practices should be applied, especially by preserving and restoring marginal semi-natural habitats, by reducing grass management intensity on paddy banks and by discouraging rice cultivation in dry soils.