Full-text - Norsk entomologisk forening

IH. trivittatus Fabr.Localities : Orre 3117 -63 (I), 1817 -65(3), Kleppe 1617 -65(7), 1518 -65 (I), Fosseikjeland 3017 -64 (I), Sele 2617 -64 (I), 1217 -65 (5), Skjzveland11/8-65 (2), 0ksnevad 21/6-64 (I), 5/8-64 (I), 11/8-64 (I),1518 -64 (I), 2217 -65 (I), 2417 -65 (I), 10/8 -65 (I), 519 -65 (I), Gimra417 -63 (2), 617 -64 (I), 1217 -64 (I), 1717 -64 (I), 517 -65 (4).Biotopes: humid bogs, borders of pools, river beds, flowerymeadows near cultivated land, sanddunes. - The species hasonly been captured in the open, never in exclusively forest terrain.It seems to be most abundant on or near relatively humidbiotopes.Plants providing nourishment: Sedum acre L. - Comarumpalustre - Valeriana offici?zalis L. - Arnica montana L. -Hieracium sp. L.Frequency: Not rare, but generally in small numbers. - D e n-m a r k : Not common, although numerous on some places. Ithas been found on Zealand, Lolland and Langeland (Lundbeck1916). Torp Pedersen (1964) finds it quite common and widelyspread on Jutland. - G r e a t B r i t a i n : "Frequent" (Coe1953).Distinguishing characteristics: The species can easily be detectedin the field by its size and relatively slender build. Theabdomen in particular is longer than in the other large Helophilusspecies, and, especially while visiting flowers, the insectcan be observed holding the back part of the abdomen lifted(Fig. 3). In profile it looks as if the insect were walking round inthe flower with "curvature of the spine". A similar feature canalso be seen with H. hybridus, but here the shorter, and relativelybroader abdomen, makes the curvature less marked.Distribution : "Regio palaearct. et neoarct." (Sack 1932). -"All Europe and down into Persia; towards the north to middleSweden ; it has also been recorded from Mexico" (Lundbeck 1916).H. pendulus L.I Localities: The species was found on all 27 localities. See Fig. 1Biotopes: Found at all the kinds of biotopes investigated.Plants providing nourishment: The species draws its nourish-I ment from a large number of plants, and given its individualabundance, one must conclude that it is an important pollinatingspecies. It has been found on the following plants: Salix repensL. - Ranunculus acris L. - Cakile maritima Scop. - Brassicarapa L. - Sedum acre - Sorbus aucuparia L. - Rubus idaeus- Cornarum palustre - Potentilla fruticosa L. - Potentillaerecta (L.) Ransch. - Calluna vulgaris (L.) Hull - T7acciniummyrtillus L. - Myosotis sp. L. - Valeriana officinalis - Succisa