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Orientation of flying locusts, Schistocerca gregaria (Forsk.), in migrating swarms

Published online by Cambridge University Press:  10 July 2009

Z. Waloff
Z. Waloff
Affiliation:
Centre for Overseas Pest Research*, College House, Wrights Lane, London W8 5SJ
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Extract

In eastern Africa between 1951 and 1955 and in south-western Morocco in 1960, orientations and densities of flying locusts in migrating swarms of Schistocerca gregaria Forsk. were recorded photographically, with supplementary visual observations. The densities ranged from 0·0006 to 1·23 locusts/m3 (mean spacing between nearest locusts 12 and 1 m, respectively) with a median value of 0·024 locusts/m3; in 50% of the samples mean spacing was 2–4 m, suggesting a preferred distance of that order. The orientations were affected by gregarious reactions to neighbouring fliers, and to locusts in a mass. In the swarms there was a preponderance of streaming groups in which locusts headed in the same general direction; in about half of these groups the angular deviation about the mean orientation was only ±20°. In comparatively dense swarms the orientations of the lower fliers in the interiors of swarms were diverse and random in relation to wind and to the swarm track. But at the leading, the trailing and the lateral edges they were predominantly into the swarm, as the result of observed changes of headings back towards the swarm in locusts flying out beyond the main mass. The orientations of locusts photographed at about 100 m and 200–400 m above the ground were found to be predominantly in the direction of the swarm track, i.e., with wind; it is suggested that they arose from compensatory optomotor responses to retinal velocities of substrate patterns, and are consistent with Kennedy's hypothesis of optomotor orientation to wind. Among lower-flying locusts such responses appeared to become important in diffuse formations and in strong winds. Thus flight on consistently into-wind courses was repeatedly seen in low-flying diffuse formations of sexually mature locusts migrating in light winds. In stronger winds the orientations of lower fliers in all types of swarms suggested responses to unacceptable retinal velocities, which interfered with the into-the-swarm orientations on the swarm edges; the continued cohesion of swarms may thus require a wind profile in which they are not evoked below a certain level. In persistent strong wind in excess of locusts' air speeds, flight activity was reduced, and swarms exhibited low into-wind flight by locusts in small numbers. It is suggested that the characteristic downwind tracks of discrete immature swarms are set primarily by the downwind orientations of their higherflying members. In sexually mature swarms the downwind displacements are probably performed mainly by the denser and the higher-rising swarms, while the into-wind flights of low diffuse formations would slow down movement, and could result in limited displacement up-wind.

Type
Original Articles
Information
Bulletin of Entomological Research , Volume 62 , Issue 1 , July 1972 , pp. 1 - 72
Copyright
Copyright © Cambridge University Press 1972

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References

Batschelet, E. (1965). Statistical methods for the analysis of problems in animal orientation and certain biological rhythms.—vi + 57 pp. Washington, D.C., American Institute of Biological Sciences.Google Scholar
Burtt, E. T. & Catton, W. T. (1956). Electrical responses to visual stimulation in the optic lobes of the locust and certain other insects.—J. Physiol., Lond. 133, 68–88.CrossRefGoogle ScholarPubMed
Burtt, E. T. & Catton, W. T. (1969). Resolution of the locust eye measured by rotation of radial striped patterns.—Proc. R. Soc. (B), 173, 513–529.Google Scholar
Campan, R., Gallo, A. & Quennec, Y. (1965). Détermination électrorétinographique de la fréquence critique de fusionnement visuel: étude comparative portant sur les yeux composés de dix-sept espèces d'insectes.—C.r. Séanc. Soc. Biol. 159, 2521–2526.Google Scholar
Chapman, R. F. (1959). Observations on the flight activity of the red locust, Nomadacris septemfasciata (Serville).—Behaviour 14, 300–334.CrossRefGoogle Scholar
Cheu, S. P. (1952). Changes in the fat and protein content of the African migratory locust, Locusta migratoria migratorioides (R. & F.).—Bull. ent. Res. 43, 101–109.CrossRefGoogle Scholar
Cochemé, J. (1966). Wind opportunities for locust transport and concentration in India and West Pakistan, June 20–30, 1961.—59 pp.Rome, F.A.O. (Progress Report UNSF/DL/RFS/6).Google Scholar
Collet, T. (1971). Visual neurones for tracking moving targets.—Nature, Lond. 232, 127–130.CrossRefGoogle Scholar
Cotterell, G. S. (1931). The occurrence of the migratory locust (Locusta migratoria migratorioides) in the Gold Coast and its dependencies during 1930.—Bull. Dep. Agric. Gold Cst 23, 255–281.Google Scholar
Durand, D. & Greenwood, J. A. (1958). Modifications of the Rayleigh Test for uniformity in analysis of two-dimensional orientation data.—J. Geol. 66, 229–238.CrossRefGoogle Scholar
Ellis, P. E. & Ashall, C. (1957). Field studies on diurnal behaviour, movement and aggregation in the desert locust (Schistocerca gregaria Forskål).—Anti-Locust Bull. no. 25, 94 pp.Google Scholar
Flöhn, H. (1965). Contributions to a synoptic climatology of north-east Africa.—Tech. Notes Wld met. Org. no. 69, 236–244.Google Scholar
Giblett, M. A. et al. (1932). The structure of wind over level country. Report of experiments carried out at the Royal Airship Works, Cardington.—Geophys. Mem., Lond. no. 54, 120 pp.Google Scholar
Gillett, S. (1968). Airborne factor affecting the grouping behaviour of locusts.—Nature, Lond. 218, 782–783.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
Haskell, P. T. (1957). The influence of flight noise on behaviour in the desert locust Schistocerca gregaria (Forsk.).—J. Insect Physiol. 1, 52–75.CrossRefGoogle Scholar
Haskell, P. T. (1960). The sensory equipment of the migratory locust.—Symp. zool. Soc. Lond. no. 3, 1–23.Google Scholar
Haskell, P. T., Paskin, M. W. J. & Moorhouse, J. E. (1962). Laboratory observations on factors affecting the movements of hoppers of the desert locust.—J. Insect Physiol. 8, 53–78.CrossRefGoogle Scholar
Kennedy, J. S. (1951). The migration of the desert locust (Schistocerca gregaria Forsk.). I. The behaviour of swarms. II. A theory of long-range migrations.—Phil. Trans. R. Soc. (B) 235, 163–290.Google Scholar
Matthews, G. V. T. (1955). Animal migration [Report of Section D's symposium on migration held at the British Association Meeting, Bristol 1955].—Nature, Lond. 176, 772–773.CrossRefGoogle Scholar
Michel, R. (1969). Étude experimentale des variations de la tendance au vol au cours du vieillissement chez le criquet pèlerin Schistocerca gregaria (Forsk.).—Rev. Comp. Anim. 3 (4), 46–65.Google Scholar
Norris, M. J. (1954). Sexual maturation in the desert locust (Schistocerca gregaria Forskål) with special reference to the effects of grouping.—Anti-Locust Bull, no. 18, 44 pp.Google Scholar
Norris, M. J. (1963). Laboratory experiments on gregarious behaviour in ovipositing females of the desert locust (Schistocerca gregaria (Forsk.)).—Entomologia exp. appl. 6, 279–303.CrossRefGoogle Scholar
Norris, M. J. (1970). Aggregation response in ovipositing females of the desert locust, with special reference to the chemical factor.—J. Insect Physiol. 16, 1493–1515.CrossRefGoogle Scholar
Phipps, J. (1950). The maturation of the ovaries and the relation between weight and maturity in Locusta migratoria migratorioides (R. & F.).—Bull. ent. Res. 40, 539–557.CrossRefGoogle Scholar
Popov, G. B. (1954). Notes on the behaviour of swarms of the desert locust (Schistocerca gregaria Forskål) during oviposition in Iran.—Trans. R. ent. Soc. 105, 65–77.CrossRefGoogle Scholar
Popov, G. B. (1958). Note on the frequency and the rate of oviposition in swarms of the desert locust (Schistocerca gregaria Forskål).—Entomologist's mon. Mag. 94, 176–180.Google Scholar
Rainey, R. C. (1951). Weather and the movements of locust swarms: a new hypothesis.—Nature, Lond. 168, 1057–1060.CrossRefGoogle Scholar
Rainey, R. C. (1957). Biometeorology and the displacements of airborne insects.—Int. J. Bioclim. Biomet. 2 pt. III, sect. B, 5 pp.Google Scholar
Rainey, R. C. (1958 a). Some observations on flying locusts and atmospheric turbulence in eastern Africa.—Q. Jl R. met. Soc. 84, 334–354.CrossRefGoogle Scholar
Rainey, R. C. (1958 b). The use of insecticides against the desert locust.—J. Sci. Fd Agric. 9, 677–692.CrossRefGoogle Scholar
Rainey, R. C. (1962). Some effects of environmental factors on movements and phase-change of locust populations in the field.—Colloques int. Cent. natn. Rech. scient. no. 114, 175–199.Google Scholar
Rainey, R. C. (1963). Meteorology and the migration of desert locusts. Applications of synoptic meteorology in locust control.—Anti-Locust Mem. no. 7, 115 pp. (Also as Tech, Notes Wld met. Org. no. 54.)Google Scholar
Rainey, R. C. & Sayer, H. J. (1953). Some recent developments in the use of aircraft against flying locust swarms.—Nature, Lond. 172, 224–228.CrossRefGoogle Scholar
Rainey, R. C. & Waloff, Z. (1951). Flying locusts and convection currents.—Anti-Locust Bull. no. 9, 51–70.Google Scholar
Rainey, R. C., Waloff, Z. & Burnett, G. F. (1957). The behaviour of the red locust (Nomadacris septemfasciata Serville) in relation to the topography, meteorology and vegetation of the Rukwa rift valley, Tanganyika.—Anti-Locust Bull. no. 26, 96 pp.Google Scholar
Roffey, J. (1969). Radar studies on the desert locust, Niger, September–October 1968.—Occ. Rep. Anti-Locust Research Centre no. 17, 14 pp.Google Scholar
Roffey, J. & Popov, G. (1968). Environmental and behavioural processes in a desert locust outbreak.—Nature, Lond. 219, 446–450.CrossRefGoogle Scholar
Sayer, H. J. (1956). A photographic method for the study of insect migration.—Nature, Lond. 177, 226.CrossRefGoogle Scholar
Sayer, H. J. (1962). The desert locust and tropical convergence.—Nature, Lond. 194, 330–336.CrossRefGoogle Scholar
Schaefer, G. W. (1972). Radar detection of individual locusts and swarms.—In Hemming, C. F. & Taylor, T. H. C. Eds. (1972). 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.379–380. London, Centre for Overseas Pest Research.Google Scholar
Scorer, R. S. (1965). Notes on middle-scale motions affecting locust swarms.—Tech. Notes Wld met. Org. no. 69, 265–273.Google Scholar
Shaw, B. (1965). Depressions and associated desert locust swarm movements in the Middle East.—Tech. Notes Wld met. Org. no. 69, 194–198.Google Scholar
Stower, W. J. (1963). Photographic techniques for the analysis of locust ‘hopper’ behaviour.—Anim. Behav. 11, 198–205.CrossRefGoogle Scholar
Stower, W. J., Popov, G. B. & Greathead, D. J. (1958). Oviposition behaviour and egg mortality of the desert locust (Schistocerca gregaria Forskål) on the coast of Eritrea.—Anti-Locust Bull. no. 30, 33 pp.Google Scholar
Taylor, L. R. (1960). The distribution of insects at low levels in the air.—J. Anim. Ecol. 29, 45–63.CrossRefGoogle Scholar
Thorson, J. (1964). Dynamics of motion perception in the desert locust.—Science N.Y. 145, 69–71.CrossRefGoogle ScholarPubMed
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. (1958). The behaviour of locusts in migrating swarms. (Abstr.)—10th Int. Congr. Ent., Montreal 1956, 2, 567–569.Google Scholar
Waloff, Z. (1960). Fat content changes in migrating desert locusts (Schistocerca gregaria Forsk.) (Abstr.)—11th Int. Congr. Ent., Vienna 1960, 1, 735.Google Scholar
Waloff, Z. (1962). Flight activity of different phases of the desert locust in relation to plague dynamics.—Colloques int. Cent. natn. Rech. scient. no. 114, 201–216.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: an historical survey.—Anti-Locust Mem. no. 8, 111 pp.Google Scholar
Waloff, Z. (1972 a). The plague dynamics of the desert locust, Schistocerca gregaria (Forsk.).—In Hemming, C. F. & Taylor, T. H. C. Eds. (1972). 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.343–349. London, Centre for Overseas Pest Research.Google Scholar
Waloff, Z. (1972 b). Observations on the airspeeds of freely-flying locusts.—Anim. Behav. 20, 366–371.CrossRefGoogle 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, 1–50.Google Scholar
Weis-Fogh, T. (1949). An aerodynamic sense organ stimulating and regulating flight in locusts.—Nature, Lond. 164, 873–874.CrossRefGoogle ScholarPubMed
Weis-Fogh, T. (1952). Fat combustion and metabolic rate of flying locusts. Schistocerca gregaria (Forskål).—Phil. Trans. R. Soc. (B) 237, 1–36.Google Scholar
Weis-Fogh, T. (1956). Biology and physics of locust flight. II. Flight performance of the desert locust (Schistocerca gregaria).—Phil. Trans. R. Soc. (B) 239, 459–510.Google Scholar
de Wet, W. J. & Webb, D. van V. (1952). Field observations on the behaviour of hoppers of the brown locust in the swarming phase.—Sci. Bull. Dep. Agric. For. Un. S. Afr. no. 337, 38 pp.Google Scholar
Wright, R. H. (1958). The olfactory guidance of flying insects.—Can. Ent. 90, 81–89.CrossRefGoogle Scholar
Yinon, U., Shulov, A. & Tsvilich, R. (1971). Audition in the desert locust: behavioural and neurophysiological studies.—J. exp. Biol. 55, 713–725.CrossRefGoogle Scholar