Studies on Simuliidae (Diptera) with particular reference to Austrosimulium tillyardianum.
Degree GrantorUniversity of Canterbury
Degree NameDoctor of Philosophy
The aim of my thesis is to present information on population changes in the common New Zealand simuliid Austrosimulium (Austrosimulium) tillyardianum Dumbleton. Larvae of this species live in riffle areas of open-country streams. Before this aim could be achieved, it was necessary to define the identity of the study animal and its relationships with other New Zealand Simuliidae, and gain an understanding of its life history. Wainui Valley Stream (43º 49'S, 172º 54’E), Banks Peninsula was chosen as the study area to undertake these investigations on population changes (p.165). A. tillyardianum was the only simuliid present in the stream, larvae were readily available throughout the year, and also there were few other species present thus reducing the amount of possible interspecific interactions. The stream was sufficiently small in size to simplify sampling procedures. Counteracting these favourable aspects were the unfavourable factors of the Wainui Valley being a popular holiday area, and the presence of a Y.M.C.A. camp site by the stream. Because of these two factors, it was considered inadvisable to leave equipment at the stream to monitor continuously stream temperature and water level which were thought to influence population size. The results of my investigations are contained in the series of papers which follow. The three main papers of the study are presented first, followed by four supporting papers on aspects not restricted to A. tillyardianum. Finally, three general interest papers and data of the instar determination and population sampling studies are included, as appendices. Each paper is complete in itself, and has been written in the style and format of the journal in which it has been (or will be) published, or to which it will be submitted.