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

  title={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},
  author={Peter Onyango Odiyo},
  journal={International Journal of Tropical Insect Science},
  • P. Odiyo
  • Published 1 December 1981
  • Environmental Science
  • International Journal of Tropical Insect Science
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… 

A Guide to Seasonal Changes in the Distribution of Armyworm Infestations in East Africa

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

Inter- and intra-seasonal variation in outbreak distribution of the armyworm, Spodoptera exempta (Lepidoptera: Noctuidae), in eastern africa

Reports of the African armyworm, Spodoptera exempta, in eastern Africa for sixteen seasons were analysed together with weather records to identify the most frequent locations of outbreaks and their relationships with weather.

African armyworm outbreaks: why do they occur after drought?

The existence of a delayed indirect effect of drought on outbreak development of the African armyworm is postulated, based on the knowledge that the decomposition of organic material by bacteria in a soil after wetting is correlated with the duration and temperature of the drying period to which the soil has been exposed.

Distribution of the African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae), and the frequency of larval outbreaks in Africa and Arabia

In parts of Africa and in south-western Arabia it is now regularly a seasonally important pest; examples are given of monthly distribution maps of the frequency of its attacks in this region.

The bionomics of the African armyworm Spodoptera exempta in relation to its status as a migrant pest

The importance and value of developing and implementing a long-term monitoring system over a large region, in this case in Africa, not only for the generation of data used by the forecasters for the prediction and location of possible outbreaks, but also for obtaining a clearer understanding of the epidemiology of a highly mobile pest.

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

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.

Forecasting the Severity of Armyworm Seasons in East Africa from Early Season Rainfall

Results suggest that early season rainfall totals, either from specific likely source areas or countrywide, could be used in January to give a seasonal forecast of likely numbers of armyworm outbreaks during the rest of the season.

Survival and Development of the African Armyworm Spodoptera exempta (Wlk.) (Lepidoptera, Noctuidae) on Some Grass Species (Gramineae)

C. dactylon is a preferred natural food plant of S. exempta in the field, and these investigations demonstrate its value and importance.

The Role of Migration in the Life System of the African Armyworm Spodoptera Exempta

The relevant aspects of a multidisciplinary study into the dispersal behaviour and re-concentration of moths, migratory flight, source areas, population upsurges and the seasonal movement of moth are reviewed.


The manifestations of Fall Armyworm [FAW] (Spodoptera frugiperda) in South Africa were all clearly reminders of the seriousness of this epidemic in 2019. The scare caused by FAW as an African Moth



Seasonal changes in distribution of the African armyworm, Spodoptera exempta (Wlk.) (Lep., Noctuidae), with special reference to eastern Africa

Seasonal successions of moth catches and outbreaks of larvae have provided repeated evidence of a progressive northward movement of populations of S. exempta, developing in March in Tanzania and Kenya, and extending across Ethiopia, in some years as far as northern Eritrea by June.

The significance of low-density populations of the African armyworm Spodoptera exempta (Walk.)

Analysis of weather patterns on the estimated dates of arrival of the moths responsible for fourteen groups of outbreaks in Rhodesia suggest that outbreaks could often be caused by convergent windflow concentrating low-density moth populations from sources between Rhodesia and the Mozambique coast, and that these sources may persist for several months.

Forecasting Infestations of a Migrant Pest: The African Armyworm Spodoptera exempta (Walk.)

A service for forecasting infestations of the larvae of Spodoptera exempta in Kenya, Tanzania and Uganda has been in operation since 1969; it uses nightly moth catches from a network of light traps,

The genus Spodoptera (Lepidoptera, Noctuidae) in Africa and the Near East.

A history of the changes in nomenclature within the genus Spodoptera is outlined. A key to the imagines of the eight species occurring in Africa and the Near East is presented, together with keys to