Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-15T01:27:03.558Z Has data issue: false hasContentIssue false
  • English
  • Français

A guide to seasonal changes in the distribution of armyworm infestations in East Africa

Published online by Cambridge University Press:  19 September 2011

Peter Onyango Odiyo
Peter Onyango Odiyo
Affiliation:
Desert Locust Control Organization for Eastern Africa (DLCO-EA) and Kenya Agricultural Research Institute (KARI), Muguga, P.O. Box 30148, Nairobi, Kenya
Get access

Abstract

The African armyworm, the larva of the night flying moth Spodoptera exempta (Walk.), feeds on young stages of cereal crops, sugar-cane and all types of grasses in some 30 countries of Africa, from Mauritania and Senegal in the north-west to Ethiopia and Somalia in the north-east, and southwards to Namibia and South Africa. Between 1960 and 1982, outbreaks of armyworms were recorded regularly in East Africa during the ‘outbreak season’ between November/December and June/July, often from southern Tanzania towards the north or north-west at monthly intervals. Analysis of occurrence of outbreaks in Tanzania, Kenya and Uganda in the 1971/72–1973/74 seasons, and rainfall records in Tanzania for 1969–1975, showed that the occurrence of armyworms in Tanzania coincided with the onset and northward progression of the rains up to Kenya and Uganda. Additional results from monthly maps, tables, graphs and histograms of armyworm occurrences in administrative units (Districts and Provinces) in Tanzania, Kenya and Uganda for 20 years (1960–1979), showed that the onset, progress and duration of armyworm attacks in all districts and provinces in each country, tend to follow certain geographical patterns which can be monitored through the use of insect traps and Agricultural Extension Services. In this way, coordinated surveillance of priority areas could enable farmers, pastoralists, Plant Protection and Pest Control Units of the Ministries of Agriculture to identify likely areas and periods of armyworm attacks, so that they could organize strategic or emergency control of armyworms with insecticides when the larvae are still young.

Keywords

OutbreaksAfrican armywormSpodoptera exemptacereal cropsgrassesAfricaTanzaniaKenyaUgandaoff-seasonoutbreak seasonadministrative unitsArmyworm Forecasting Servicestrategic controlseasonal rains
Type
Research Articles
Information
International Journal of Tropical Insect Science , Volume 5 , Issue 2 , April 1984 , pp. 107 - 119
Copyright
Copyright © ICIPE 1984

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

REFERENCES

Aidley, D. J. (1974) Migratory capability of the African Armyworm moth, Spodoptera exempta (Walk.). E. Afr. agric. For. J. 40, 202–203.CrossRefGoogle Scholar
Betts, E. (1976) Forecasting infestations of tropical migrant pests: the desert locust and the African armyworm. 7th Symp. R. ent. Soc. Lond. 7, 113–134.Google Scholar
Boer, M. H. Den (1978) Isoenzymes and migration in the African armyworm, Spodoptera exempta (Lepidoptera, Noctuidae). J. Zool. Lond. 185, 539–553.CrossRefGoogle Scholar
Brown, E. S. (1962) The African Armyworm, Spodoptera exempta (Walker) (Lepidoptera, Noctuidae). A review of the literature. Multigraph, Commonw. Inst. Entom. London.Google Scholar
Brown, E. S. (1970) Control of the African Armyworm, Spodoptera exempta (Walk.) an appreciation of the problem. E. Afr. agric. For. J. 35, 237–245.CrossRefGoogle Scholar
Brown, E. S., Betts, E. and Rainey, R. C. (1969) Seasonal changes in distribution of the African armyworm with special reference to eastern Africa. Bull. ent. Res. 58, 661–728.Google Scholar
Brown, E. S. and Odiyo, P. O. (1968) The rate of feeding of the African Armyworm, Spodoptera exempta (Walk.) and its significance for control operations. E. Afr. agric. For. J. 33, 245–256.CrossRefGoogle Scholar
Brown, E. S. and Swaine, G. (1966) New evidence on the migration of moths of the African armyworm. Bull. ent. Res. 56, 671–814.CrossRefGoogle Scholar
Commonwealth Institute of Entomology (1972) Spodoptera exempta (Walk.). Distrib. Maps Insect Pests 53.Google Scholar
East African Meteorological Department (EAMD) (1975) Climatological Statistics for East Africa parts I and III, Nairobi, Kenya.Google Scholar
Haggis, M. J. (1971) Light trap catches of Spodoptera exampta (Walk.) in relation to wind direction. E. Afr. agric. For. J. 37, 100–108.CrossRefGoogle Scholar
Hattingh, C. C. (1941) The biology and ecology of the armyworm (Laphygma exempta) and its control in South Africa. Sci. Bull. Dep. Agric. S. Afr. 217, 50.Google Scholar
Khasimuddin, S. (1981) Behavioural ecology of the African armyworm, Spodoptera exempta (Walker): Observations on population processes during a high density outbreak. Insect Sci. Applic. 1, 143–146.Google Scholar
Odiyo, P. O. (1979) Forecasting infestations of a migrant pest: the African armyworm Spodoptera exempta (Walk.) (Lepidoptera, Noctuidae). Phil. Trans. R. Soc. Lond. B. 287, 403–413.Google Scholar
Odiyo, P. O. (1981) Development of the first outbreak of the African armyworm, Spodoptera exempta (Walk.) between Kenya and Tanzania during the ‘off-season’ months of July to December. Insect Sci. Applic. 1, 305–318.Google Scholar
Persson, B. I. P. (1981) Population fluctuations of the African armyworm, Spodoptera exempta (Walk.) (Lepidoptera, Noctuidae), in outdoor cages in Kenya. Bull. ent. Res. 71, 289–297.CrossRefGoogle Scholar
Rainey, R. C. (1976) (Editor) Insect Flight. 7th Symp. R. ent. Soc. Lond. 5, 75–112.Google Scholar
Riley, et al. (1981) Radar observations of Spodoptera exempta, Kenya, March-April 1979. Centre of Overseas Pest Research Misc. Rep. pp. 43–54.Google Scholar
Rose, D. J. W. (1975) Field development and quality changes in successive generations of Spodoptera exempta (Walk.), the African armyworm J. appl. Ecol. 21, 727–739.Google Scholar
Rose, D. J. W. and Dewhurst, C. F. (1979) The African armyworm, Spodoptera exempta (Walk.)—congregation of moths in trees before flight. Ent. exp. appl. 26, 346–348.CrossRefGoogle Scholar
Tomsett, J. E. (1969) Average monthly and annual rainfall maps of East Africa. East African Meteorological Department (E.A.M.D.), Technical Memorandum No. 14, Nairobi, Kenya.Google Scholar