Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-10T14:47:50.061Z Has data issue: false hasContentIssue false

Cereal Losses Caused by Armyworm in Eastern and Southern Africa: Current Information and Research Proposals

Published online by Cambridge University Press:  19 September 2011

D. J. W. Rose
Affiliation:
Desert Locust Control Organisation for Eastern Africa, Armyworm Project, P.O. Box 30023, Nairobi, Kenya, East Africa
M. J. Iles
Affiliation:
Overseas Development Natural Resources Institute, Central Avenue, Chatham Maritime, Chatham, Kent, ME4 4TB, UK
A. Ward
Affiliation:
Overseas Development Natural Resources Institute, Central Avenue, Chatham Maritime, Chatham, Kent, ME4 4TB, UK
Get access

Abstract

Armyworm, Spodoptera exempta (Wlk.) feed on cereals and grassland in eastern and southern Africa. Data on the yield losses and economic effects of an attack on cereals is sparse. They can be an indirect cause of cattle deaths. The need to examine the situation at the farm level has been recognized. A national survey was conducted in 1987, and is currently being analysed. The work entails identifying representative areas and farmers, completing a questionnaire with each farmer, noting the frequency of outbreaks experienced, the farmers' response, the level of government support, the effectiveness of control measures and the costs incurred. Proposals are outlined for future work within the region to determine the reduction in cereal yields due to this insect and to set up action thresholds for control activities. A major difficulty with the survey approach is the disaggregation of various loss-causing factors. At a sub-sample of survey sites, where outbreaks are present, the damage to the crop and the subsequent yield of the damaged crop or the planting of a replacement crop would be recorded to build up data from which action thresholds might be determined.

Résumé

Les chenilles legionnaires, Spodoptera exempta (Wlk.), se nourrissent des cereales et des terres de l'herbe dans l'Afrique de l'est et du sud et sont la cause indirecte de la mort du betail. Les données sur la perte de la recolte et les effets economiques d'une attaque sur les cereales sont peu abondantes. Des propositions pour le travail dans la region a l'avenir sont esquissees pour determiner la reduction en recolte à cause de cet insecte et pour etablir des seuils d'action pour les activités de controle. Le travail comprendra l'identification des régions et des fermiers representatives et le remplissement par chaque fermier d'une questionnaire, en prenant note du nombre des eruptions, de la reaction des fermiers, du niveau de l'appui du gouvernement, de l'efficacité des mesures de controle et des couts réalisés. Dans les mêmes endroits ou les eruptions se présentent, on enregistrera la destruction de la récolte, et enfin la récolte après la destruction, ou la poussée d'une récolte de remplacement, afin d'établir des données pour déterminer les seuils d'action.

Type
Research Article
Copyright
Copyright © ICIPE 1988

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

Brown, E. S. and Mohamed, K. A. (1972) The relation between simulated armyworm damage and crop loss in maize and sorghum. E. Afr. Agric. For. J. 38, 237257.CrossRefGoogle Scholar
Brown, E. S. and Odiyo, P. (1968) The rate of feeding of the African armyworm Spodoptera exempta (Walk.) and its significance for control operations. E. Afr. Agric. For. J. 33, 245256.CrossRefGoogle Scholar
Bryson, R. W. (1982) Kikuyu poisoning and the armyworm. J. Afr. Vet. Assoc. 53, 161165.Google Scholar
Cruz, I. and Turpin, F. T. (1983) Yield impact of larval infestations of the fall armyworm to midwhorl growth stage of corn. J. econ. ent. 76, 10521054.CrossRefGoogle Scholar
Haggis, M. J. (1984) Distribution, frequency of attack and seasonal incidence of the African armyworm Spodoptera exempta (Walk.) (Lepidoptera: Noctuidae) with particular reference to Africa and south western Arabia. TDRI, L69, iv + 116 pp.Google Scholar
Harrison, F. P. (1984) The development of an economic injury level for low populations of fall armyworm (Lepidoptera: Noctuidae) in grain corn. Flor. Ent. 67, 335339.CrossRefGoogle Scholar
Iles, M. J. (1986) An economic assessment of the African armyworm with special reference to Tanzania: Research proposals. (Internal report to the Government of Tanzania) TDRI, London.Google Scholar
Kieckhefer, R. W. and Kantack, B. H. (1980) Losses in yield in spring wheat in South Dakota caused by cereal aphids. J. Econ. Ent. 73, 582585.CrossRefGoogle Scholar
Levine, E., Clement, S. L. and McCartney, D. A. (1984) Effect of seedling injury by the stalk borer (Lepidoptera: Noctuidae) on regrowth and yield of corn. J. econ. ent. 77, 167170.CrossRefGoogle Scholar
Mulder, P. G. and Showers, W. B. (1986) Defoliation by the armyworm (Lepidoptera: Noctuidae) on field corn in Iowa. J. Econ. Ent. 79, 369373.CrossRefGoogle Scholar
Newsholm, S. T., Kellermanm, T. S., Westhuizen, G. C. A. and Soley, J. T. (1983) Intoxification of cattle on Kikuyu grass following Spodoptera exempta invasion. Ond. J. Vet. Res. 50, 157167.Google Scholar
Odiyo, P. (1979) Forecasting infestation of a migrant pest: The African armyworm Spodoptera exempta (Walk). Phil. Trans. R. Soc. Lond. B287, 403413.Google Scholar
Vorst, J. J. (1969) Influence of defoliation and stand reduction on Zea mays L. Thesis, University of Nebraska.Google Scholar
Watts, J. G., Huddleston, E. W. and Owens, J. C. (1982) Rangeland entomology. A. Rev. Ent. 27, 283311.CrossRefGoogle Scholar