Het genus Renocera (Sciomyzidae) in Nederland

Abstract

The known distribution of the three Renocera species (Sciomyzidae) in The Netherlands is discussed. All species are uncommon, R. pallida is relatively most present, R. striata is the rare one. The distribution of both species appeared not to be linked to regions in the Netherlands but to nature areas with real wet conditions; the distribution is scattered. R. stroblii appears to be present in different locations from the other two, perhaps in less wet conditions. The flight period appeared to be in middle of May and beginning of August for R. pallida and R. striata; R. stroblii is about two weeks later. The results prove the presence of two generations a year. Compared with data before 1950 R. stroblii is present in equal numbers; R. pallida and especially R. striata are less encountered in recent times. The discussion evaluates the reproduction and the relation between larvae and small clams. In some locations the presence of Pisidium species could not be proved, making the preferred relation between Renocera larvae and clams doubtful.