A study of Sminthurus viridis (L.) (Collembola) in the Western Cape Province

Thesis (MScConsEcol)--Stellenbosch University, 1964.

ENGLISH ABSTRACT: Investigations on Sminthurus viridis (L.) in the winter rainfall region of South Africa are described. The food plants, distribution, history of occurrence-in South Africa and economic importance of the species are discussed. A detailed description of the species is presented and it is further demonstrated that colour variation in this species appears to be dependent on prevailing temperature conditions and is of little, if any, taxonomic value. The granting of specific status to the variety nigromaculate is shown to be invalid. The various stages of development and the habits of the pest are described. The influence of temperature, relative humidity, soil moisture conditions, soil texture, soil reaction, food plant relations, and population density on the biology of the pest were investigated and the results of these investigations are presented. A new method for the conduct of population surveys of the pest in the field is described. The seasonal history of the pest at Caledon was investigated during 1961 and 1962 with especial attention being paid to the influence of grazing practices and variation in meteorological conditions on fluctuation in population density. Observations on the occurrence of the pest on irrigated pastures during the summer months are also discussed. It is concluded that : the major factor influencing the occurrence and activities of the pest in this region is variation in moisture conditions.

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Masters