Behavioural Ecology of the African Armyworm, Spodoptera Exempta (Walker): Observations on Population Processes During a High-Density Outbreak
During sporadic outbreaks of S. exempta, population densities sometimes reach extremely high numbers. Monitoring at one such outbreak revealed that a considerable synchrony exists in the developmental processes of such populations, so that at times up to 97% of the population is represented by only one stage of development. Heavy pupal mortality with symptoms of a cytoplasmic virus infection was noted. Flight behaviour of emerging adults revealed observable differences in the flight activity of the moths. Although a great majority of the emerging moths flew away from the area, some stayed back. Eggs layed by the latter produced a second brood but, due to a more or less total depletion of the food source, this subsequent brood did not survive in any appreciable numbers and finally died out.
Key WordsSpodoptera exempta resource utilization migratory drive flight behaviour
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- Brown E. S. (1962) The African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae) A review of literature. Commonwealth Institute of Entomology, London, 57 pp., 11 tables.Google Scholar