Full-text - Norsk entomologisk forening

Fig. I. Thorax. dorsal view, of Piophila flava.trap was positioned close to a good habitat forthe species. The biology and habitat of the larvaeof p, flava are unknown, but the conspicuousdifference between Blesbekken no 3 1981 andthe other sites, was that Blesbekken no 3 1981has much more grassy areas nearby. The terrestrialground at the other sites are either muchdrier or much more wet, with heather or mosses,respectively. We assume that a good larvalhabitat in the subalpine birch belt is ground coveredwith grass.The total flight period of P. flava in the Dovremountain cover July until early October. Themedian, or the time when 50 % of the summertotal eatch of individuals occurred was 11 August1981 and 31 July in 1980. This difference iscertainly caused by a much later spring in 1981than in 1980.G0thberg (1973) showed that some terrestrialinsects also fly upstream as many aquatic insectsdo (Muller 1982), and the two sided Malaisetraps used at some sites gave data about an ups- ,tream or a downstream flight ,direction. Theupstream and downstream catches of females ofP. flava are not significantly different from eachTable I. Numbers of individuals of Piophila flava collected in Malaise traps during 1980 and 1981, in the areaof Kongsvoll, Dovre mountains, Sr-Trondelag province. D =Downstream side, U =Upstream side of Malaisetrap, M =Male, F =Female, • =p