Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-16T16:29:08.005Z Has data issue: false hasContentIssue false

Observations on the Life-history of the Red Locust, Nomadacris septemfasciata (Serv.) in the solitary Phase

Published online by Cambridge University Press:  10 July 2009

G. F. Burnett
Affiliation:
Late of the International Red Locust Control Service, Abercorn, Northern Rhodesia.

Extract

The populations of Nomadacris septemfasciata described in this paper were all of solitaria or neai-solitaria phase.

Sexual maturation as measured by the developing ovaries took place rapidly though irregularly through the population. Its onset coincided with an increase in the daily number of hours of relative humidity at or above 75 per cent., and abundance of green food; Copulation, which started after the first wide-spread rain, took place before the ovaries of many females were completely mature.

Caged locusts gave a mean fecundity of 183 eggs contained in 2·4 pods which is probably a minimum figure. Pods were laid at intervals of about two weeks and each was laid before the next batch had visibly developed.

The period spent in the egg was at least 39 days, at most 46 days and probably 42 days. Adults appeared 67 days after the first hatchings. Both these periods are greater than those recorded in phase transiens or gregaria.

Solitaria locusts were found to pass through seven instead of six nymphal instars as do gregaria. This difference seemed to be constant. The extra instar was probably interpolated between the second and third of gregaria but was not an exact duplicate of any other instar.

The number of vertical dark eye-stripes is a convenient and fairly constant indicator of the instar. The number of antennal segments in the later instars and in the adult, and also the number of adult eye-stripes, is greater in the solitaria phase.

Amongst the hoppers three main types of coloration were encountered and are briefly described but they could not be closely related to phase. The amount of dark pigment present in late stage nymphs was reflected in the young adult, the appearance of which is described in some detail. Subsequent changes during the dry season are briefly noted, in particular the pink of the hind wing, which becomes faintly visible within a month of the last moult.

The changes in pigmentation which take place during sexual maturation are described in detail. In addition to pronounced darkening of the tegmina which completely changes the appearance of the solitaria locust, certain bright pigments are laid down which are later obscured by a general blackening. It is unsafe to classify Nomadacris septemfasciata as to phase on colour alone unless the date of capture and its relation to the breeding season in the locality is taken into consideration. Solitaria do not normally develop the general reddening of the body which is shown by migrating swarms, even when these are only transiens in phase.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1951

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

Brédo, H. J. (1938). Phases du Nomadacris septemfasciata Serv. au Congo Belge.—C.R.Ve Conf. in Rech. antiacrid., Brussels, pp. 406409, 6 figs.Google Scholar
Burnett, G. F. (1951). Field observations on the behaviour of the Red Locust in the solitary phase.—Anti-Locust Bull., London, no. 8.Google Scholar
Egypt, . (1937). Proceedings of the Fourth International Locust Conference,Cairo,April 22, 1936.97 pp., 51 appendices.Google Scholar
Faure, J. C. (1932). The phases of locusts in South Africa.—Bull. ent. Res., 23, pp. 293424, 1 map, 25 pls.CrossRefGoogle Scholar
Faure, J. C. (1935). The life history of the Red Locust (Nomadacris septemfasciata (Serville) ).—Bull. Dep. Agric. S. Afr., no. 144, 32 pp., 1 map, 5 pis.Google Scholar
Gunn, D. L., Lea, H. A. F. & others. (1948). Locust control by aircraft in Tanganyika.—153 pp., 10 pls., 32 figs. London, Anti-Locust Res. Centre.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, pp. 160, 2 pls., 26 figs.CrossRefGoogle Scholar
Johnston, H. B. & Buxton, D. R. (1949). Field observations on locusts in eastern Africa.—Anti-Locust Bull., London, no. 5, 74 pp., 3 maps, 5 pls., 3 figs.Google Scholar
Key, K. H. L. (1936). Observations on rate of growth, coloration, and the abnormal six-instar life-cycle in Locusta migratoria migratorioides, R. & F.Bull. ent. Res., 27, pp. 7785, 4 figs.CrossRefGoogle Scholar
Lea, A. (1938). Investigations on the Red Locust, Nomadacris septemfasciata (Serv.), in Portuguese East Africa and Nyasaland in 1935.—Sci. Bull. Dep. Agric. S. Afr., no. 176, 29 pp., 4 figs.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., 20 figs.Google Scholar
Michelmore, A. P. G. & Allan, W. (1934). Observations on phases of the Red-winged Locust in Northern Rhodesia.—Bull. ent. Res., 25, pp. 101428, 5 figs.CrossRefGoogle Scholar
Mossop, M. C. (1933). Description of hopper instars of the Red Locust, Nomadacris septemfasciata, Serv. phase gregaria, and some changes in adult coloration.—Proc. Rhod. sci. Ass., 32, pp. 113118.Google Scholar
Mukerji, S. & Batra, R. N. (1938). A note on the post-embryonic development of eye-stripes and their correlation with the number of larval instars and the antennal segments in the life-cycle of Schistocerca gregaria Forsk.—C.R.Ve Conf. in Rech. antiacrid., Brussels, pp. 410415, 3 tables.Google Scholar
Roonwal, M. L. (1940). Preliminary note on some directional changes among locusts and other Acrididae, and the importance of the third instar.—Indian J. Ent., 2, pp. 137144, 1 fig.Google Scholar
Roonwal, M. L. (1946). Studies in intraspecific variation. II. New rules governing the correlation between normal- and extra-moulting and directional reversal of the elytron-wing complex in the Desert Locust and other Acrididae (Orthoptera).—Indian J. Ent., 7, (1945), pp. 7784.Google Scholar
Smee, C. (1936). Notes on the Red Locust (Nomadacris septemfasciata, Serv.) in Nyasaland 1933–34.—Bull. ent. Res., 27, pp. 1535, 1 map, 12 figs.CrossRefGoogle Scholar
Thomas, J. G. (1941). The relative size of the eye as a phase character in the African Migratory Locust.—Bull. ent. Res., 31, pp. 431433, 1 fig.CrossRefGoogle Scholar
Uvarov, B. P. (1928). Locusts and grasshoppers. A handbook for their study and control. xiii+352 pp., 9 pls., 118 figs. London, Imp. Bur. Ent.Google Scholar
Uvarov, B. P. (1933). Preliminary experiments on the annual cycle of the Red Locust (Nomadacris septemfasciata, Serv.).—Bull. ent. Res., 24, pp. 419420.CrossRefGoogle Scholar
Volkonsky, M. (1938). Stries oculaires et âges larvaires chez les acridiens.—Arch. Inst. Pasteur Algérie, 16, pp. 523532, 11 figs.Google Scholar
Zolotarevsky, B. N. (1933). Contribution à l'étude biologique du criquet migrateur (Locusta migratoria capito, Sauss.) dans ses foyers permanents.—Ann. Epiphyt., 19 pp. 47142, 1 map, 1 pl., 1 fig., 13 graphs.Google Scholar