Sökning: "mayfly"

Hittade 3 avhandlingar innehållade ordet mayfly.

1. 1. Visual ecology of insect superposition eyes

   Författare :Pär A Brännström; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Animal physiology; tiger beetle; hawkmoth; mayfly; insect; visual ecology; eye design; vision; compound eye; Djurfysiologi;

   Sammanfattning : In the superposition compound eye each rhabdom (light sensitive unit) receives light through many ommatidial facets, while in the apposition compound eye every rhabdom receives light from a single facet. The superposition design increases photon capture, which is an advantage in dark environments. LÄS MER

3. 2. Lateral movements versus stationarity : adaptive alternatives in benthic invertebrates to the seasonal environment in a boreal river

   Författare :Tommy I. Olsson; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Benthic invertebrates; cold-hardiness; ice; migrations; overwintering; river; seasonal variations; spatial distribution; spring flood; water level;

   Sammanfattning : Benthic invertebrates inhabiting boreal rivers are exposed to very large seasonal variations in their physical environment. The extremes are in winter when the littoral area freezes solid and in spring when water flow increases rapidly. LÄS MER

4. 3. Competition in caddis larvae

   Författare :Göran Englund; S. Kohler; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Agrypnia pagetana; Arctopsyche ladogensis; emigration; fighting behaviour; habitat selection; Hydropsyche siltalai; Hydropsychidae; immigration; predation; resource competition; sequential assessment game;

   Sammanfattning : This thesis deals with behavioural strategies used by caddis larvae in pairwise contests and when selecting microhabitats. Effects of caddis larvae on survival and habitat selection of other insect taxa have also been studied. LÄS MER