Mitarbeitende

The dragonfly and damselfly monitoring carried out in ten Swiss paddy fields in 2019 and 2020 revealed 42 species. Of these, 14 species developed in the fields, of which ten are bivoltine (Ischnura elegans, I. pumilio, Anax ephippiger, A. imperator, A. parthenope, Crocothemis erythraea, Orthetrum albistylum, O. brunneum, O. cancellatum, Sympetrum fonscolombii) and four univoltine (Sympecma fusca, Sympetrum depressiusculum, S. striolatum, S. vulgatum). The discovery of exuviae of S. depressiusculum, S. striolatum, and S. vulgatum in July 2020 documented their development and the survival of the eggs during the harvest in October and the preparation of the plots for sowing and planting in May. A mass emergence of a second generation of A. ephippiger and S. fonscolombii was observed in 2019. Population estimates for the Brugg site amounted to thousands or even tens of thousands of individuals, confirming the attractiveness of this habitat for the development of both migratory species in Central Europe. For A. ephippiger, the year 2019 corresponds to one of the largest known influxes in Switzerland and Europe over the last thirty years. The proven development of S. depressiusculum in the rice field of Ins suggests that rice fields have a conservatory significance for this threatened species.