Do Trichoptera in running water fly upstream?
Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
Drift moves aquatic insects downstream, risking depopulation of upstream reaches. However, the necessity and exist-ence of an upstream flight to compensate for drift has not been undisputed. I analysed a sample of approximately 70
000 Trichoptera from a stream in northern Sweden collected during one season in 1974. The overall flight direction
was upstream. Females had a stronger upstream flight than males and species varied in both flight direction and
strength of the preference. Flight direction was not affected by wind or trap type. Upstream flight varied during the
season and with different larval behaviours. Upstream flight increased with the size of the imago and with the abun-dance in flight. A colonisation cycle might be in effect but even though upstream flight occurs, it might not be neces-sary to sustain populations in upstream reaches.
Place, publisher, year, edition, pages
2015. , 42 p.
Trichoptera, drift, colonisation cycle, upstream flight
IdentifiersURN: urn:nbn:se:liu:diva-130870ISRN: LiTH-IFM-G-Ex--15/3026--SEOAI: oai:DiVA.org:liu-130870DiVA: diva2:956088
Subject / course
2015-06-03, Linköpings universitet, 581 83 LINKÖPING, Linköping, 11:24 (Swedish)