Hostname: page-component-848d4c4894-pftt2 Total loading time: 0 Render date: 2024-05-19T18:27:17.428Z Has data issue: false hasContentIssue false

The development and termination of the 1968 plague of the desert locust, Schistocerca gregaria (Forskål) (Orthoptera, Acrididae)

Published online by Cambridge University Press:  10 July 2009

L. V. Bennett
Affiliation:
Centre for Overseas Pest Research, College House, Wrights Lane, London W8 5SJ, U.K.

Abstract

The population dynamics of the desert locust, Schistocerca gregaria* (Forsk.), in Africa, the Middle East and Asia from 1966 to 1969 have been analysed to determine the causes of the beginning and the abrupt end of the plague of 1968. Evidence indicates that in 1966 there were no persistent sequences of breeding by gregarious populations, but in 1967 and early 1968 there were four sequences of breeding by initially solitary behaving locusts, each resulting in a substantial increase in numbers and density. These events led to a plague that ended by mid-1969.

The threshold rainfall requirement for successful breeding, defined as an increase in numbers from mature adults of the parent generation to filial fledglings, has been related to the rainfall required for the germination of ephemerals and their growth to sizes that can provide food and shelter for hoppers throughout their development. It is suggested that the minimum quantity of rainfall required initially over a large area is 25 mm. This requirement is usually met in the summer breeding areas. Rainfall in the winter-spring breeding areas is more variable, and falls exceeding the threshold are most commonly associated with deep troughs in the mid- and upper-tropospheric westerly winds in winter and spring. A season in which many such troughs occur may be essential for plague development. It is also suggested that the timing of successive periods of rainfall allowing successful breeding is critical in determining the occurrence of upsurges.

Control against non-gregarious infestations failed to contain the upsurge, but later control measures against hopper bands and swarms contributed to the plague decline. The most economical strategy for plague prevention might be one of upsurge elimination, that is to say control in selected areas against gregarious locusts only. The implications of adopting such a strategy are discussed.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1976

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ashall, C. (1972). Theories of locust control. In Hemming, C. F. & Taylor, T. H. C. (Eds) Proceedings of the international study conference on the current and future problems of acridology. London, United Kingdom, 61607 1970. Convened by and to mark the Silver Jubilee of the Anti-Locust Research Centre.—459–464. London, Centre for Overseas Pest Research.Google Scholar
Bennett, L. V. (1974). Factors affecting the upsurge and decline of populations of the desert locust (Schistocerca gregaria Forskål) in 1966–1969.—2 vols. Ph.D. Thesis, London University.Google Scholar
Bennett, L. V. & Symmons, P. M. (1972 a). A review of estimates of numbers in some types of desert locust (Schistocerca gregaria (Forsk.)) populations.—Bull. ent. Res. 61, 637649.CrossRefGoogle Scholar
Bennett, L. V. & Symmons, P. M. (1972 b). A review of estimates of the effectiveness of certain control techniques and insecticides against the desert locust.—Anti-Locust Bull. no. 50, 15 pp.Google Scholar
Davies, D. E. (1952). Seasonal breeding and migrations of the desert locust (Schistocerca gregaria Forskål) in north-eastern Africa and the Middle East.—Anti-Locust Mem. no. 4, 56 pp.Google Scholar
Dirsh, V. M. (1953). Morphometrical studies on phases of the desert locust (Schistocerca gregaria Forskål).—Anti-Locust Bull. no. 16, 34 pp.Google Scholar
Dirsh, V. M. (1974). Genus Schistocerca (Acridomorpha, Insecta).—238 pp., The Hague, W. Junk, Ser. Ent. vol. 10.Google Scholar
Donnelly, U. (1947). Seasonal breeding and migrations of the desert locust (Schistocerca gregaria Forskål) in western and north-western Africa.—Anti-Locust Mem. no. 3, 42 pp.Google Scholar
Dudley, B. A. C. (1961). Studies on the biology of locusts when reared under controlled conditions.—Ph.D. Thesis, Cardiff University.Google Scholar
F.A.O. (1956). Report of the FAO panel of experts on long-term policy of desert locust control held in London, England, 92004 1956.—26 pp. Rome, FAO (FAO Meeting Report no. 1956/11).Google Scholar
Fortescue-Foulkes, J. (1953). Seasonal breeding and migrations of the desert locust (Schistocerca gregaria Forskål) in south-western Asia.—Anti-Locust Mem. no. 5, 35 pp.Google Scholar
Greathead, D. J. (1966). Notes on Blaesoxipha spp. (Dipt., Calliphoridae) parasitising Acridoidea in eastern Africa.—Tech. Bull. Commonw. Inst. biol. Control, no. 7, 9199.Google Scholar
Gunn, D. L. (1960). The biological background of locust control.—A. Rev. Ent. 5, 279300.CrossRefGoogle Scholar
Gunn, D. L., Perry, F. C, Seymour, W. G., Telford, T. M., Wright, E. N. & Yeo, D. (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
Hamilton, A. G. (1936). The relation of humidity and temperature to the development of three species of African locusts—Locusta migratoria migratorioides (R & F), Schistocerca gregaria (Forsk.), Nomadacris septemfasciata (Serv.).—Trans. R. ent. Soc. Lond. 85, 160.CrossRefGoogle Scholar
Hamilton, A. G. (1950). Further studies on the relation of humidity and temperature to the development of two species of African locusts.—Locusta migratoria migratorioides (R & F) and Schistocerca gregaria (Forsk.).—Trans. R. ent. Soc. Lond. 101, 158.Google Scholar
Hemming, C. F. & Symmons, P. M. (1969). The germination and growth of Schouwia purpurea (Forsk.) Schweinf. and its role as a habitat of the desert locust.—Anti-Locust Bull. no. 46, 38 pp.Google Scholar
Hunter-Jones, P. (1964). Egg development in the desert locust (Schistocerca gregaria Forsk.) in relation to the availability of water.—Proc. R. ent. Soc. Lond. (A) 39, 2533.Google Scholar
Husain, M. A. & Ahmad, T. (1936). Studies on Schistocerca gregaria Forsk. II. The biology of the desert locust with special relation to temperature.—Indian J. agric. Sci. 6, 188262.Google Scholar
Johnston, H. B. (1926). A further contribution to our knowledge of the bionomics and control of the migratory locust Schistocerca gregaria Forsk. (peregrina Oliv.), in the Sudan.—Bull. Wellcome trop. Res. Labs. (ent.) no. 22, 14 pp.Google Scholar
Karrar, A. M. H. M. (1972). The pattern and causes of invasions of Sudan by swarms of the desert locust (Schistocerca gregaria, Forsk.) together with studies of some relevant aspects of flight behaviour.—Ph.D. Thesis, London University.Google Scholar
Kassas, M. (1966). Plant life in deserts. In Hills, E. S. (Ed.) Arid lands: a geographical appraisal.—145180. London, Methuen; Paris, Unesco.Google Scholar
Kendrew, W. G. (1953). The climates of the Continents. 4th edn.—607 pp. Oxford, Clarendon Press.Google Scholar
Luntz, A. J. (1968). Neurosecretory activity and growth during reproduction and development in Schistocerca gregaria Forskål.—M.Sc. Thesis, Sheffield University.Google Scholar
Magor, J. I. (1962). Rainfall as a factor in the geographical distribution of the desert locust breeding areas, with particular reference to the summer breeding area of India and Pakistan.—Ph.D. Thesis, Edinburgh University.Google Scholar
Norris, M. J. (1952). Reproduction in the desert locust (Schistocerca gregaria Forsk.) in relation to density and phase.—Anti-Locust Bull. no. 13, 49 pp.Google Scholar
Norris, M. J. (1957). Factors affecting the rate of sexual maturation of the desert locust (Schistocerca gregaria Forskal) in the laboratory.—Anti-Locust Bull. no. 28, 26 pp.Google Scholar
Pedgley, D. E. (1969). Cyclones along the Arabian coast.—Weather, Lond. 24, 456469.CrossRefGoogle Scholar
Pedgley, D. E. (1970 a). An unusual monsoon disturbance over southern Arabia. In Proceedings of the symposium on tropical meteorology. University of Hawaii, Honolulu, 09 211 1970.—E VI 1–7. American Meterological Society & World Meteorological Organization.Google Scholar
Pedgley, D. E. (1970 b). A heavy rainstorm over north-western Arabia. In Proceedings of the symposium on tropical meteorology. University of Hawaii, Honolulu, 09 211 1970.—E VII 1–7. American Meteorological Society & World Meteorological Organization.Google Scholar
Pedgley, D. E. (1974). E.R.T.S. surveys a 500 km2 locust breeding site in Saudi Arabia. In Freden, F. C, Mercanti, E. P. & Becker, M. A. (Eds.). 3rd Earth Resources Technology Satellite—I Symposium, December 1973. Vol. 1, 233246. Washington, N.A.S.A.Google Scholar
Petterssen, S. (1956). Weather analysis and forecasting. 2nd edn.—Vol. 1, 628 pp.; Vol. 2, 266 pp. New York, Toronto & London, McGraw-Hill.Google Scholar
Popov, G. B. (1958). Ecological studies on oviposition by swarms of the desert locust (Schistocerca gregaria Forskål) in eastern Africa.—Anti-Locust Bull. no. 31, 70 pp.Google Scholar
Popov, G. B. (1965). Review of the work of the Desert Locust Ecological Survey, June 1958– March 1964 and the considerations and conclusions arising from it.—80+15 pp. Rome, FAO. (FAO Report no. UNSF/DL/ES/8).Google Scholar
Popov, G. B. (1968). Locust survey in Oman, 11 January to 3 March, 1968.—Occ. Rep. anti-Loc. Res. Cent. no. 13/68, 19 pp.Google Scholar
Rainey, R. C. (1951). Weather and the movements of locust swarms: a new hypothesis.—Nature, Lond. 168, 10571060.CrossRefGoogle Scholar
Rainey, R. C. (1963 a). Meteorology and the migration of desert locusts. Applications of synoptic meteorology in locust control.—Anti-Locust Mem. no. 7, 115 pp.Google Scholar
Rainey, R. C. (1963 b). Aircraft reconnaissance and assessment of locust populations.—2nd Int. agric. Aviat. Congr., Grignon, 1962. 228233.Google Scholar
Rainey, R. C. (1968). Some implications of the present status of the desert locust (Schistocerca gregaria Forsk.) (Abstr.).—13th Int. Congr. Ent., Moscow, 1968, Vol. 2, 379.Google Scholar
Rainey, R. C. (1973). Airborne pests and the atmospheric environment.—Weather, Lond. 28, 224239.CrossRefGoogle Scholar
Rainey, R. C. & Sayer, H. J. (1953). Some recent developments in the use of aircraft against flying locust swarms.—Nature, Lond. 172, 224228.CrossRefGoogle Scholar
Ramage, C. S. (1971). Monsoon meteorology.—296 pp. New York & London, Academic Press.Google Scholar
Rao, Y. R. (1942). Some results of studies on the desert locust (Schistocerca gregaria Forskål) in India.—Bull. ent. Res. 33, 241265.Google Scholar
Rao, Y. R. (1960). The desert locust in India.—721 pp. New Delhi, Indian Council of Agricultural Research.Google Scholar
Roffey, J. (1963). Observations on gliding in the desert locust.—Anim. Behav. 11, 359366.CrossRefGoogle Scholar
Roffey, J. (1969). Radar studies on the desert locust.—Occ. Rep. anti-Loc. Res. Cent. no. 17/69. 17 pp.Google Scholar
Roffey, J. & Popov, G. B. (1968). Environmental and behavioural processes in a desert locust outbreak.—Nature, Lond. 219, 446450.CrossRefGoogle Scholar
Roffey, J., Popov, G. B. & Hemming, C. F. (1970). Outbreaks and recession populations of the desert locust Schistocerca gregaria (Forsk.).—Bull. ent. Res. 59, 675680.CrossRefGoogle Scholar
Rungs, C. (1946). Rapport sur les essais de lutte contre les adultes de Schistocerca gregaria Forsk. au Maroc francais, au printemps de 1945.—Bull. Off. natn. anti-acrid. Algér. no. 2: 4187.Google Scholar
Shreve, F. (1951). Vegetation and flora of the Sonoran Desert. Vol. I. Vegetation of the Sonoran Desert.—Publs Carnegie Instn no. 591, 192 pp.Google Scholar
Symmons, P. M. (1969). A morphometric measure of phase in the desert locust, Schistocerca gregaria (Forsk.).—Bull. ent. Res. 58, 803809.CrossRefGoogle Scholar
Symmons, P. M., Green, S. M., Robertson, R. A. & Wardhaugh, K. G. (1973). Incubation and hopper development periods of the Desert Locust.—156 sheets and guide. London, Centre for Overseas Pest Research.Google Scholar
Symmons, P. M., Green, S. M., Robertson, R. A. & Wardhaugh, K. G. (1974). The production of distribution maps of the incubation and hopper development periods of the desert locust Schistocerca gregaria (Forsk.) (Orthoptera, Acrididae).—Bull. ent. Res. 64, 443451.CrossRefGoogle Scholar
Taylor, S. A. (1961). Water relations in field crops. In Plant-water relationships in arid and semi-arid conditions. Proceedings of the Madrid Symposum.—303308. Paris, Unesco.Google Scholar
United States Department of Commerce (1967). World Weather Records 1951–1960.— Vol. 4, Asia; Vol. 5, Africa.Google Scholar
Uvarov, B. P. (1921). A revision of the genus Locusta L. (=Pachytylus Fieb.) with a new theory as to the periodicity and migrations of locusts.—Bull. ent. Res. 12, 135163.CrossRefGoogle Scholar
Uvarov, B. P. (1966). Grasshoppers and locusts. A handbook of general acridology. Vol. 1.—481 pp. Cambridge University Press.Google Scholar
Waloff, Z. (1946). Seasonal breeding and migrations of the desert locust (Schistocerca gregaria Forskål) in eastern Africa.—Anti-Locust Mem. no. 1, 74 pp.Google Scholar
Waloff, Z. (1963). Field studies on solitary and transiens desert locusts in the Red Sea area.—Anti-Locust Bull. no. 40, 93 pp.Google Scholar
Waloff, Z. (1966). The upsurges and recessions of the desert locust plague: and historical survey.—Anti-Locust Mem. no. 8, 111 pp.Google Scholar
Waloff, Z. (1972). The plague dynamics of the desert locust, Schistocerca gregaria (Forsk.). In Hemming, C. F. & Taylor, T. H. C. (Eds) Proceedings of the international study conference on the current and future problems of acridology. London, United Kingdom, 6–16 July 1970. Convened by and to mark the Silver Jubilee of the Anti-Locust Research Centre.—459464. London, Centre for Overseas Pest Research.Google Scholar
Waloff, Z. (1976). Some temporal characteristics of desert locust plagues.—Anti-Locust Mem. no. 13, 36 pp.Google Scholar
Waloff, Z. & Rainey, R. C. (1951). Field studies on factors affecting the displacements of desert locust swarms in eastern Africa.—Anti-Locust Bull. no. 9, 150.Google Scholar
Wardhaugh, K., Ashour, Y., Ibrahim, A. O., Khan, A. M. & Bassonbol, M. (1969). Experiments on the incubation and hopper development periods of the desert locust (Schistocerca gregaria Forskål) in Saudi Arabia.—Anti-Locust Bull. no. 45, 38 pp.Google Scholar
Weis-Fogh, T. (1956). Biology and physics of locust flight. II. Flight performance of the desert locust (Schistocerca gregaria).—Phil. Trans., London (B) 239, 459510.Google Scholar
Went, F. W. (1953). The effects of rain and temperature on plant distribution in the desert. In Desert research. International symposium held in Jerusalem, May 7–14, 1972, sponsored by the Research Council of Israel and the United Nations Educational Scientific and Cultural Organization.—230240. Jerusalem, Research Council of Israel (Special publication no. 2).Google Scholar
Winstanley, D. (1973). Rainfall patterns and general atmospheric circulation.—Nature, Lond. 245, 190194.CrossRefGoogle Scholar