Theunis Johannes Naudé, economic entomologist, was the son of Willem Johannes Naudé and his wife Maria Elizabeth. He received his secondary education at Heilbron High School where he matriculated (through the University of the Cape of Good Hope) in 1915. The next year he entered Grey University College, Bloemfontein, where he studied in the Arts Faculty, but he interrupted his studies for a year to serve as a teacher in the Heilbron district during World War I (1914-1918). When he returned to Bloemfontein he changed to studies in science and was awarded the Bachelor of Science (BSc) degree in botany and zoology by the University of South Africa in 1920. Subsequently he spent six months as an assistant entomologist at the Elsenburg Agricultural College near Stellenbosch. He was awarded a government overseas scholarship and in 1921 entered Ohio State University in the United States where he concentrated his research on the insect pests of maize. He was awarded the MSc degree in entomology in June 1922 and the PhD degree towards the end of 1923 with a thesis entitled Cicadellidae of South Africa - a taxonomic and faunistic study. His thesis was later published in South Africa as Entomology Memoir No. 4 (1926) and laid the foundation of the study of leaf hoppers in southern Africa. It dealt with 140 species, most of them feeders on grasses, and included two serious pests, the maize jassid and the cotton jassid, which weaken their host plants not only by sucking their sap, but also by transmitting viral diseases.

Naudé returned to South Africa in 1924 and in April that year joined the staff of the Department of Agriculture as cotton and tobacco entomologist at Rustenburg. He retained an interest in insect pests of cotton for many years, as he published two articles on the topic in Farming in South Africa in 1950 and 1964. Meanwhile in 1928 he succeeded Dr Claude Fuller* as chief entomologist of the Section of Entomology in the Division of Plant Industry in Pretoria. This section became the Division of Entomology in September 1939, with Naudé as its chief. He travelled to many parts of South Africa, initially mainly in connection with brown and red locusts pests but later to attend to many other entomological problems. In 1934 he initiated the dusting of red locust swarms from the air with sodium arsenite in the Ubombo Mountains of Zululand, using both Air Force and civil aeroplanes. He was also the first to stress the relationship between harvester termites and veld destruction, leading to soil erosion. This work formed the basis of two papers that he presented at the Entomological Conference held at Pretoria in 1936. He also played an important role in the biological control of prickly pear in the Eastern Cape.

Naudé retired in September 1958 but was appointed in a temporary position to address various agricultural problems caused by animals such as the quelea finch, a genus of small passerine birds that are a major pest to small grain cereal crops in much of sub-Saharan Africa. In 1958 he travelled to present Maputo in Mozambique and to Bulawayo, Zimbabwe, to coordinate the attacks on the quelea pest of the different states in southern Africa. The next year he discussed "The quelea problem in South Africa" in the journal Ostrich. Other zoological pest animals to which he had to devote attention were the hyrax, bush pig and spring hare. He also served as a member of the National Coordinating and Advisory Committee for Fauna Research. In 1961 he was transferred to the Transvaal region as temporary entomologist until he finally retired from government service at the end of 1969. He then joined the National Institute for Water Research at the CSIR as coordinator of some research projects until the end of 1971, when he retired to a small citrus farm near Nelspruit. He returned to Pretoria in 1977.

In May 1933 Naudé was one of the conveners (with J. C. Faure* and A. J. T. Janse*) of the inaugural meeting of the Pretoria Entomological Club. The club ceased to function in 1936. In October 1937 he became one of the founding members of the Entomological Society of South (later Southern) Africa. He was elected as the first honorary editor of the society's Journal but was succeeded the next year by J. C. Faure. In 1942 he was elected president of the society and served also as joint vice-president during 1938-1939 and 1944.

In 1930 Naudé married Dr Elizabeth Maria ("Baps") Theron, who became a well-known medical practitioner in Pretoria, and with whom he had four children. After her death in 1944 he married a widow van der Merwe (born Jones) in 1949. By nature a shy person, he was nonetheless an approachable, fair and forthright chief of his Division and a naturalist with a love of the veld and of farming. He had an extensive practical knowledge of South African entomological problems.

List of sources:

Bedford, E. C. G. The early history of the Entomological Society of Southern Africa, 1937-1960. Journal of the Entomological Society of Southern Africa, 1961, Vol. 24, pp. 3-16.

FamilySearch: Theunis Johannes Naudé. https://ancestors.familysearch.org/en/GHJV-RYK/theunis-johannes-naude-1897-1983

Farming in South Africa, March 1940, p. 84: New Chiefs of Divisions: Dr T. J. Naudé.

Google scholar. http://scholar.google.co.za/ , publications by T. J. Naudé.

Lounsbury, C. P. The pioneer period of economic entomology in South Africa. Journal of the Entomological Society of Southern Africa, 1940, Vol. 3, pp. 9-29.

Mansell, M.W. The Entomological Society of Southern Africa - a historical review. African Entomology, 1993, Vol. 1, pp. 109-120.

National Automated Archival Information Retrieval System (NAAIRS). http://national.archives.gov.za/naairs.htm Documents relating to T. J. Naudé.

Obituary: Henry Arnold Francis Lea (1907-1989). Journal of the Entomological Society of Southern Africa, 1991, Vol. 54(1), pp. 101-109.

Obituary: Theunis Johannes Naudé (1897-1983). Journal of the Entomological Society of Southern Africa, 1985, Vol. 48(2), pp. 345-346.

Smit, B. A further chapter in the history of entomology in South Africa. Journal of the Entomological Society of Southern Africa, 1960, Vol. 23, pp. 3-15.

University of the Cape of Good Hope. Calendar, 1918, Matriculation examinations.

Compiled by: C. Plug

Last updated: 2025-05-29 09:29:00