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Enumerating Populations of Adults of the Red Locust, Nomadacris septemfasciata (Serville), in its Outbreak Areas in East and Central Africa

Published online by Cambridge University Press:  10 July 2009

C. C. Scheepers
Affiliation:
International Red Locust Control Service, Abercorn, N. Rhodesia.
D. L. Gunn
Affiliation:
International Red Locust Control Service, Abercorn, N. Rhodesia.

Summary

A method is described of estimating the total numbers and frequency distributions of adults of the Red Locust, Nomadacris septemfasciata (Serv.), in outbreak areas of hundreds of square miles, based upon counting the numbers that fly up in a two-yard strip in front of a moving vehicle. The method has proved itself valuable for indicating both immediate and future requirements for killing the locusts, but it requires refining for some research purposes.

By this method, the importance has been clearly shown of the process of congregation of scattered adult locusts in forming emigrant swarms that could start a plague. The locusts do not congregate but actually disperse just before laying eggs.

The total population in part (189 sq. miles) of the North Rukwa Outbreak Area (a self-contained area of 253 sq. miles) in Tanganyika Territory has been followed for four years. There are indications that a small migrant swarm contains 5–10 million locusts, that a total population in the whole of the North Rukwa Outbreak Area of 20 million locusts is unlikely to yield a migrant swarm, but that 50 million locusts could readily do so.

In 1953, after poor rains, no natural mortality was detected between July and October by the assessment methods described. In 1957, after good rains, natural mortality of 70–90 per cent. was revealed by the same methods, although the dry season was not fully covered by the assessments.

Type
Research Paper
Copyright
Copyright © Cambridge University Press 1958

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References

Backlund, H. O.(1955). Red Locusts and vegetation.—Oikos, 6, pp. 124138.CrossRefGoogle Scholar
Backlund, H. O. (1956). Aspects and successions of some grassland vegetation in the Rukwa Valley, a permanent breeding area of the Bed Locust.—Oikos, suppl. 2, 132 pp.Google Scholar
Burnett, G. F. (1951). Field observations on the behaviour of the Red Locust (Nomadacris septemfasciata Serville) in the solitary phase.—Anti-Locust Bull., no. 8, 36 pp.Google Scholar
Davey, J. T. & Johnston, H. B. (1956). The African Migratory Locust (Locusta migratoria migratorioides R. & F.) in Nigeria.—Anti-Locust Bull., no. 22, 91 pp.Google Scholar
Gunn, D. L. (1952). The Red Locust.—J. B. Soc. Arts, 100, pp. 261284.Google Scholar
Gunn, D. L. (1955). Mweru wa Ntipa and the Red Locust.—N. Rhod. J., 2, no. 6, pp. 315.Google Scholar
Gunn, D. L. (1956). A history of Lake Rukwa and the Red Locust.—Tanganyika Notes, no. 42, pp. 118.Google Scholar
Gunn, D. L. (1957). The story of the International Red Locust Control Service.—Rhod. agric. J., 54, pp. 824.Google Scholar
Gunn, D. L., Lea, H. A. F. & others. (1948). Locust control by aircraft in Tanganyika.—153 pp. London, Anti-Locust Res. Cent.; Pretoria, Locust Contr. Ees. Sect., Dep. Agric.Google Scholar
Gunn, D. L., Perry, F. C. & others. (1948). Behaviour of the Desert Locust (Schistocerca gregaria Forskål) in Kenya in relation to aircraft spraying.—Anti-Locust Bull., no. 3, 70 pp.Google Scholar
Lea, A. & Webb, D., van, V. (1939). Field observations on the Red Locust at Lake Rukwa in 1936 and 1937.—Sci. Bull. Dep. Agric. S. Afr., no. 189, 81 pp.Google Scholar
Michelmore, A. P. G. (1939). Observations on tropical African grasslands.—J. Ecol., 27, pp. 282312.CrossRefGoogle Scholar
Pielou, E. C. (1952). Notes on the vegetation of the Rukwa Rift Valley, Tanganyika.—J. Ecol., 40, pp. 383392.CrossRefGoogle Scholar
Ramchandra Rao, Y. (1942). Some results of studies on the Desert Locust (Schistocerca gregaria Forsk.) in India.—Bull. ent. Res., 33, pp. 241265.CrossRefGoogle Scholar
Richards, O. W. (1953). The study of the numbers of the Red Locust, Nomadacris septemfasciata (Serville).—Anti-Locust Bull., no. 15, 28 pp.Google Scholar
Smit, C. J. B. (1939). Field observations on the Brown Locust in an outbreak centre.—Sci. Bull. Dep. Agric. S. Afr., no. 190, 143 pp.Google Scholar
Uvarov, B. P. (1951). Locust research and control, 1929–1950.—Colon. Res. Publ., no. 10, 67 pp.Google Scholar
Vesey-FitzGerald, D. F. (1955). The vegetation of the outbreak areas of the Red Locust (Nomadacris septemfasciata Serv.) in Tanganyika and Northern Rhodesia.—Anti-Locust Bull., no. 20, 31 pp.Google Scholar