摘要:

Investigations carried out in a coastal stream flowing to the Northern Bothnian Sea (Ängerån, 63°35'N, 19°50'E) have shown a high drift rate of mayfly nymphs towards the coastal areas. The nymphal development takes place in the estuaries with low salinity (conductivity between 47 and 9800 μS; salinity between 0 and 4–5%0). After the emergence (May/June) the adults fly from the coastal areas to lay their eggs in the stream biotope in the Ängerån. There thus appears to be a colonization cycle between the coastal stream and adjacent coastal areas. The migration movements of downstream drift and the compensatory upstream directed flight are interpreted as asurvival strategy of the species concerned.

ISSN:0165-0424    

DOI:10.1080/01650427909360986

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Several larval, pupal, and adult specimens ofAphropsyche monticolaFlint were collected from a locality in Pennsylvania. Examination of this material led to the association of the immature forms of the genusAphropsycheby the metamorphotype method. The larvae will key toAphropsyche?in Wiggins (1977), who has tentatively assigned the larval form of this genus.

ISSN:0165-0424    

DOI:10.1080/01650427909360987

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

An interesting and unusual instance of swarm‐feeding was observed when large numbers of the damselfly,Hetaerina americanafed on hatches of mayfly subimagos over riffle areas of the White River in Indiana. The phenomenon of swarm‐feeding in Odonata is reviewed and delineated and the behavior observed forH. americanadiffers considerably from previously observed patterns.

ISSN:0165-0424    

DOI:10.1080/01650427909360988

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Annual and seasonal variations of individual weights of dominant species of aquatic insects in Breitenbach, Germany, are described and the probable reasons of variations are discussed. Variations are not correlated in different species, and there appears to be no uniform explanation of the phenomenon.

ISSN:0165-0424    

DOI:10.1080/01650427909360989

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Two new chironomid species,Rheotanytarsus illiesisp. n. (from Breitenbach, Schlitz, Germany) andBrillia subviridissp. n. (from Kematen near Inns bruck, Austria) are described.

ISSN:0165-0424    

DOI:10.1080/01650427909360990

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The known African Ephemeridae presently consists of three genera and seven nominal species. Adults and larvae ofAfromera evaesp.n. aredescribed from The Gambia. The genusAfromerais recognized as being distinct fromEphemeraand is evidently equivalent to the subgenusDicrephemera(ofEphemera)which is thus synonymized. Larvae of African Ephemeridae are keyed to genus, and adults are keyed to species. Thestudy of African burrowing may flies may be advanced by sampling the insect drift of large silt‐bottomed rivers for the poorly known larvae. The biogeographical affinities of the Ephemeridae of Africa (south of the Sahara) lie with tropical Asia and not with other southern continents. Evolution and dispersal probably were not affected by continental drift. Ecological differences betweenAfromeraandEphemeraare predicted to be relatively consistent throughout the Afro‐Asian area.

ISSN:0165-0424    

DOI:10.1080/01650427909360991

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Necterosoma wollastoni(Clark 1862) is synonymized withN. undecimlineatum(Babington 1841). Distributional data forN. regulareSharp 1882 are presented, and polymorphism and distribution ofN. penicillatum(Clark 1862) are discussed.N. susannasp. n. (Victoria and New South Wales) is described and illustrated. Probable relationships between all species are discussed.

ISSN:0165-0424    

DOI:10.1080/01650427909360992

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The larvae ofTrinotoperla irrorata Tillyard(Gripopterygidae) possess remarkable chlorid cells consisting of one central cell and at least one adjacent cell grouped together into a small cell complex. They are termed floriform chloride cells because of the flower‐bud‐like structures seen by scanning electron miroscopy. Fine structural studies in combination with histochemical demonstration of chloride indicate that these cell complexes probably participate in osmoregulation by the absorption of salt.

ISSN:0165-0424    

DOI:10.1080/01650427909360993

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0165-0424    

DOI:10.1080/01650427909360994

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:0165-0424    

DOI:10.1080/01650427909360985

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor