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Predicting the severity of Spodoptera exempta (Lepidoptera: Noctuidae) outbreak seasons in Tanzania

Published online by Cambridge University Press:  10 July 2009

A.W. Harvey  and
G.A. Mallya
A.W. Harvey*
Affiliation:
Ministry of Agriculture, Arusha, Tanzania
G.A. Mallya
Affiliation:
Ministry of Agriculture, Arusha, Tanzania
*
A. W. Harvey, Natural Resources Institute, Chatham Maritime, Chatham, Kent ME4 4TB, UK.
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Abstract

Outbreaks of the African armyworm, Spodoptera exempta (Walker), in East Africa follow a seasonal pattern related to the movement of the inter-tropical convergence zone. The season typically begins in central Tanzania with primary outbreaks that coincide with the arrival of the rains. An analysis of 27 years' light trap records shows a high negative correlation between the total number of moths caught by light traps during the season over the whole country and the number of rain days during November in central Tanzania. Out of the 27 seasons, 22 could have been correctly predicted as ‘light’ or ‘severe’, using the November rainfall at one station, Dodoma, in time to give two months' warning before the peak of the season.

Type
Original Articles
Information
Bulletin of Entomological Research , Volume 85 , Issue 4 , December 1995 , pp. 479 - 487
Copyright
Copyright © Cambridge University Press 1995

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