Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-01T21:31:52.117Z Has data issue: false hasContentIssue false

Forecasting the severity of seasonal outbreaks of African armyworm, Spodoptera exempta (Lepidoptera: Noctuidae) in kenya from the previous year's rainfall

Published online by Cambridge University Press:  10 July 2009

M.J. Haggis*
Affiliation:
Natural Resources Institute, Chatham, UK
*
M.J. Haggis, Natural Resources Institute, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK.

Abstract

Rainfall records for 23 years at 21 selected stations in Kenya were summarized and compared with the numbers of outbreaks of armyworm Spodoptera exempta (Walker) reported in the following season. The numbers of outbreaks were found to be negatively correlated with the rainfall of the 6–8 months preceding the start of the season. Stations in south-eastern Kenya, including the coastal belt which harbours the most extensive off-season source populations of S. exempta, were identified as key stations for forecasting whether to anticipate local or countrywide armyworm outbreaks next season. A scheme is suggested that would enable a provisional forecast to be made as soon as the long rains (April–May) rainfall records were available, and confirmed or revised subsequently in the light of the June–October rainfall at stations in south-eastern Kenya.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1996

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

Belts, E. (1976) Forecasting infestations of tropical migrant pests: the Desert Locust and the African Armyworm. pp. 113134 in Rainey, R.C. (Ed.). Insect flight. Oxford, Blackwell Scientific (Symposium, Royal Entomological Society of London No. 7).Google Scholar
Betts, E., Rainey, R.C., Brown, E.S., Mohamed, A.K.A. & Odiyo, P. (1971) Armyworm forecasting service. Record of Research Annual Report of the East African Agriculture & Forestry Research Organization 1970, 103105.Google Scholar
Brown, E.S. & Swaine, G. (1965) Virus disease of the African armyworm, Spodoptera exempta (Wlk.). Bulletin of Entomological Research 56, 95116.CrossRefGoogle Scholar
Brown, E.S., Betts, E. & Rainey, R.C. (1969) Seasonal changes in distribution of the African armyworm, Spodoptera exempta (Wlk.) (Lep. Noctuidae), with special reference to eastern Africa. Bulletin of Entomological Research 58, 661728.CrossRefGoogle Scholar
Brown, E.S., Odiyo, P.O., Betts, E., Sondergard, K.M.M. & Onyango, J. (1972) Armyworm forecasting service, 1970/71 season. Record of Research Annual Report of the East African Agriculture & Forestry Research Organization 1971, 199202.Google Scholar
East African Agriculture and Forestry Research Organization (1965) Record of research: Annual report 1964. Nairobi, East African Common Services Organization.Google Scholar
East African Meteorological Department (EAMD) (1972) Summary of rainfall in Kenya for the year 1970. 42 pp. Nairobi, East African Community.Google Scholar
Haggis, M.J. (1984) Distribution, frequency of attack and seasonal incidence of the African armyworm Spodoptera exempta (Walk.) (Lep.: Noctuidae), with particular reference to Africa and southwestern Arabia. iv + 116 pp. Report of the Tropical Development and Research Institute, L69.Google Scholar
Haggis, M.J. (1986) Distribution of the African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae), and the frequency of larval outbreaks in Africa and Arabia. Bulletin of Entomological Research 76, 151170.CrossRefGoogle Scholar
Hattingh, C.C. (1941) The biology and ecology of the armyworm (Laphygma exempta) and its control in South Africa. 50 pp. Science Bulletin No. 217, Department of Agriculture and Forestry, Union of South Africa.Google Scholar
Kenya Agricultural Research Institute (1986) Agricultural Research Department Record of Research: Annual report 1977–1980. Nairobi, Kenya Agricultural Research Institute.Google Scholar
Kenya Meteorological Department (KMD) (1984) Climatological statistics for Kenya. 87 pp. Nairobi, Kenya Meteorological Department.Google Scholar
Meteorological Department (1965) Summary of rainfall in Kenya for the year 1964. 39 pp. Nairobi, East African Common Services Organization.Google Scholar
Meteorological Office (1972) Meteorological glossary. 319pp. London, HMSO.Google Scholar
Mörth, H.T. (1970) A study of the areal and temporal distributions of rainfall anomalies in East Africa, pp. K II, 17 in Proceedings, Symposium on Tropical Meteorology, Honolulu, June 1970,American Meteorological Society and WMO.Google Scholar
Odindo, M.O. (1983) Epizootiological observations on a nuclear polyhedrosis of the African armyworm Spodoptera exempta (Walk.). Insect Science and its Application 4, 291298.Google Scholar
Odiyo, P.O. (1979) Forecasting infestations of a migrant pest: the African armyworm Spodoptera exempta (Walk.). Philosophical Transactions of the Royal Society of London B287, 403413.Google Scholar
Odiyo, P.O. (1981) Development of the first outbreaks of the African armyworm, Spodoptera exempta (Walk.), between Kenya and Tanzania during the ‘off-season’ months of July to December. Insect Science and its Application 1, 305318.Google Scholar
Odiyo, P.O. (1990) Progress and developments in forecasting outbreaks of the African armyworm, a migrant moth. Philosophical Transactions of the Royal Society of London B328, 555569.Google Scholar
Page, W.W. (1984) The field programme in East Africa. Workingpaper, Seminar on the African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae), TDRI, London, September 1984. TDRI unpublished report.Google Scholar
Persson, B. (1981) Population fluctuations of the African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae), in outdoor cages in Kenya. Bulletin of Entomological Research 71, 289297.CrossRefGoogle Scholar
Rose, D.J.W., Dewhurst, C.F. & Page, W.W. (1986) Armyworm biology. Record of Research Annual Report Kenya Agricultural Research Institute Agricultural Research Department 1981, 8788.Google Scholar
Tucker, M.R. (1984a) Forecasting the severity of armyworm seasons in East Africa from early season rainfall. Insect Science and its Application 5, 5155.Google Scholar
Tucker, M.R. (1984b) Possible sources of outbreaks of the armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae), in East Africa at the beginning of the season. Bulletin of Entomological Research 74, 599607.CrossRefGoogle Scholar
Tucker, M.R., Mwandoto, S. & Pedgley, D.E. (1982) Further evidence for windborne movement of armyworm moths, Spodoptera exempta, in East Africa. Ecological Entomology 7, 463473.CrossRefGoogle Scholar
Tucker, M.R. & Pedgley, D.E. (1983) Rainfall and outbreaks of the African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae). Bulletin of Entomological Research 73, 195199.CrossRefGoogle Scholar