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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

Published online by Cambridge University Press:  19 September 2011

Peter Onyango Odiyo
Peter Onyango Odiyo
Affiliation:
Kenya Agricultural Research Institute (KARI), Muguga, P.O. Box 30148, Nairobi, Kenya
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Abstract

Occurrences of outbreaks of the African armyworm, Spodoptera exempta, between January and December for 19 years (1961–1979), and records on nightly moth catches from light trap stations located between southern Kenya and east-central Tanzania (1–8°S and 35–41°E) for 16 years (1963–1978), have been mapped, tabulated, and analysed on a standard weekly time-table, in order to compare events occurring between the ‘off-season’ months of July to November and the beginning of the ‘outbreak seasons’ from December or January. Circumstantial evidence from the above, coupled with analysis of climatological statistics for rainfall, temperature and windflow over the area and period, support the hypothesis that populations of S. exempta can survive between southern Kenya and eastcentral Tanzania during the off-season months, and contribute to the initial development of ‘outbreak seasons’ in Tanzania or Kenya. Methods for monitoring and analysing such developments for improving the efficiency of the Armyworm Forecasting Service in East Africa are suggested.

Keywords

OutbreaksAfrican armywormSpodoptera exemptaKenyaTanzaniaoff-seasonArmyworm Forecasting Service
Type
Research Article
Information
International Journal of Tropical Insect Science , Volume 1 , Issue 4 , December 1981 , pp. 305 - 318
Copyright
Copyright © ICIPE 1981

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References

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