Hostname: page-component-77c89778f8-m42fx Total loading time: 0 Render date: 2024-07-20T21:53:16.987Z Has data issue: false hasContentIssue false

Occurrence of the grasshopper pest Zonocerus variegatus (L.) (Orthoptera: Pyrgomorphidae) in south-western Nigeria in relation to the wet and dry seasons

Published online by Cambridge University Press:  10 July 2009

W. W. Page
Affiliation:
Centre for Overseas Pest Research, College House, Wrights Lane, London W8 5SJ, UK

Abstract

An investigation into the seasonal abundance of Zonocerus variegatus (L.) around Ibadan, Nigeria, showed that hatching occurs between October and March and peak abundance is in late November. Adults occur almost throughout the year. Oviposition takes place between March and October or possibly November, with a peak in April. Eggs laid in March and April hatch in October and November after a diapause, while those laid from June onwards do not appear to enter diapause. Thus eggs laid in June and July hatch at the same time as those laid in March and April. Parasitism by the sargophagid fly Blaesoxipha filipjevi (Rod.) during March and April results in a rapid decline in adult numbers which may be followed by a secondary peak in adult numbers when nymphs, which are present at the same time and are rarely parasitised, reach adult stage. Oviposition resulting from such a peak does not produce a secondary peak in hatching as this coincides with hatching from earlier layings. The fungus Entomophthora grylli plays an important role in controlling the abundance of nymphs and adults during the dry season despite the intermittent nature of the attacks. During the wet season, the fungus is able to germinate and disperse more readily, thus keeping the numbers of the insects low. It is concluded that there is one generation of Z. variegatus a year, with a peak in population coinciding with the dry season (November-March). It is suggested from the results that the grasshopper may have originated in the semi-arid zones of the north.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1980

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

Anya, A. O. (1973). Ecology of the variegated grasshopper, Zonocerus variegatus (Orthoptera: Acridoidea, Pyrgomorphidae) on the Nsukka Plateau, Nigeria.—Entomologia exp. appl. 16, 6476.Google Scholar
Bernays, E. A., Chapman, R. F., Cook, A. G., McVeigh, L. J. & Page, W. W. (1975). Food plants in the survival and development of Zonocerus variegatus (L.).—Acrida 4, 3345.Google Scholar
Bernays, E. A., Chapman, R. F., Leather, E. M., McCaffery, A. R. & Modder, W. W. D. (1977). The relationship of Zonocerus variegatus (L.) (Acridoidea: Phrgomorphidae) with cassava (Manihot esculenta).—Bull. ent. Res. 67, 391404.CrossRefGoogle Scholar
Chapman, R. F., Cook, A. G., Mitchell, G. A. & Page, W. W. (1977). Descriptions and morphometrics of the nymphs of Zonocerus variegatus (L.) (Orthoptera: Acridoidea).—Bull. ent. Res. 67, 427437.CrossRefGoogle Scholar
Chapman, R. F., Cook, A. G., Mitchell, G. A. & Page, W. W. (1978). Wing dimorphism and flight in Zonocerus variegatus (L.) (Orthoptera: Pyrgomorphidae).—Bull. ent. Res. 68, 229242.CrossRefGoogle Scholar
Chapman, R. F., Page, W. W. & Cook, A. G. (1979). A study of population changes in the grasshopper, Zonocerus variegatus, in southern Nigeria.—J. Anim. Ecol. 48, 247270.Google Scholar
Chapman, R. F. & Page, W. W. (1978). Embryonic development and water relations of the eggs of Zonocerus variegatus (L.) (Acridoidea: Pyrgomorphidae).—Acrida 7, 243252.Google Scholar
Chapman, R. F. & Page, W. W. (1979). Factors affecting the mortality of the grasshopper, Zonocerus variegatus, in southern Nigeria.—J. Anim. Ecol. 48, 271288.CrossRefGoogle Scholar
Golding, F. D. (1940). Notes on the variegated grasshopper, Zonocerus variegatus, L., in Nigeria.—Bull. ent. Res. 30, 543550.CrossRefGoogle Scholar
Golding, F. D. (1948). The Acrididae (Orthoptera) of Nigeria.—Trans. R. ent. Soc. Lond. 99, 517587.CrossRefGoogle Scholar
Harvey, A. W. (1977). The expression of supernumerary chromosomes in Myrmeleotettix maculatus (Thunberg) (Acrididae).—Ph.D. thesis, Univ. East Anglia.Google Scholar
Jerath, M. L. (1965). Note on the biology of Zonocerus variegatus (Linnaeus) from Eastern Nigeria.—Revue Zool. Bot. afr. 72, 243251.Google Scholar
McCaffery, A. R., Cook, A. G., Page, W. W. & Perfect, T. J. (1978). Utilisation of food by Zonocerus variegatus (L.) (Orthoptera: Pyrgomorphidae).—Bull. ent. Res. 68, 589606.CrossRefGoogle Scholar
McCaffery, A. R. & Page, W. W. (1978). Factors influencing the production of long-winged Zonocerus variegatus.—J. Insect Physiol. 24, 465472.Google Scholar
Modder, W. W. D. (1978). Respiratory and weight changes, and water uptake, during embryonic development and diapause in the African grasshopper Zonocerus variegatus (L.) (Acridoidea: Pyrogomorphidae).—Acrida 7, 253265.Google Scholar
Oyidi, O. (1966). Variation and variability in orthopteran insects.—Ph.D. thesis, Univ. London.Google Scholar
Oyidi, O. (1967). Variation and variability in orthopteran insects. 1. The influence of age on chiasma frequency in Zonocerus variegatus L. (Acrididae).—Jl W. Afr. Sci. Ass. 12, 131138.Google Scholar
Oyidi, O. (1968 a). Variation and variability in orthopteran insects. 2. The correlation between chiasma frequency and terminal chiasmata in natural populations of Zonocerus variegatus L. (Acrididae).—Jl W. Afr. Sci. Ass. 13, 5360.Google Scholar
Oyidi, O. (1968 b). Variation and variability in orthopteran insects. 5. Notes on the biological status of Zonocerus variegatus L. (Acrididae) in Nigeria, with particular reference to the relationship between the dry and the wet season populations.—Jl W. Afr. Sci. Ass. 13, 159164.Google Scholar
Oyidi, O. (1972 a). Variation and variability in orthopteran insects. 3. The influence of body size as measured by size of individual insects on chiasma frequency on Zonocerus variegatus L. (Orthoptera: Pyrgomorphidae).—Nigerian J. Sci. 5, 167173.Google Scholar
Oyidi, O. (1972 b). Variation and variability in orthopteran insects. 4. Variation in chiasma frequency in seasonal populations of Zonocerus variegatus (Pyrgomorphidae) Linneus (1758).—Nigerian J. Sci. 6, 107117.Google Scholar
Oyidi, O. (1974). The variegated grasshopper, Zonocerus variegatus (Linnaeus) (Orthoptera: Pyrgomorphidae).—Samaru Agric. Newsl. 16, 8687.Google Scholar
Page, W. W. (1978 a). The biology and control of the grasshopper Zonocerus variegatus.—PANS 24, 270277.CrossRefGoogle Scholar
Page, W. W. (1978 b). Destruction of eggs as an alternative to chemical control of the grasshopper pest Zonocerus variegatus (L.) (Orthoptera: Pyrgomorphidae) in Nigeria.—Bull. ent. Res./ 68, 575581.CrossRefGoogle Scholar
Page, W. W., Harris, J. R. W. & Youdeowei, A. (1980). Defoliation and consequent crop loss in cassava caused by the grasshopper Zonocerus variegatus (L.) (Orthoptera: Pyrgomorphidae) in southern Nigeria.—Bull. ent. Res. 70, 151163.CrossRefGoogle Scholar
Page, W. W. & McCaffery, A. R. (1979). Characteristics and distribution of oviposition sites of the grasshopper zonocerus variegatus (L.).—Ecol. Ent. 4, 277288.CrossRefGoogle Scholar
Peacock, A. D. (1913). Entomological pests and problems of Southern Nigeria.—Bull. ent. Res. 4, 191220.CrossRefGoogle Scholar
Taylor, T. A. (1964). Blaesoxipha filipjevi Rohd. (Diptera, Sarcophagidae) parasitising Zonocerus variegatus (L.) (Orthopetera, Acridoidea) in Nigeria.—Bull. ent. Res. 55, 8386.Google Scholar
Taylor, T. A. (1972). On the origin of the wet-season form of Zonocerus variegatus (L.) (Orth., Acrididae) in southern Nigeria, with some biological notes.—Bull. ent. Res. 61, 661667.CrossRefGoogle Scholar
Toye, S. A. (1971). Notes on the biology of Zonocerus variegatus (L.) (Orthoptera, Acridoidea) in the Western State of Nigeria.—Revue Zool. Bot. afr. 84, 384392.Google Scholar
Uvarov, B. (1966). Grasshoppers and locusts. Vol. 1.—481 pp. Cambridge Univ Press.Google Scholar
Vuillaume, M. (1954). Étude du cycle du Zonocerus variegatus en Bass Côte d'Ivoire.—Fruits 9, 147156.Google Scholar