International Journal of Tropical Insect Science
- International Journal of Tropical Insect Science / Volume 1 / Issue 02 / June 1981, pp 143-146
- Copyright © ICIPE 1981
- DOI: http://dx.doi.org/10.1017/S1742758400000308 (About DOI), Published online: 19 September 2011
Research Article
Behavioural ecology of the african armyworm, Spodoptera exempta (Walker): Observations on population processes during a high-density outbreak
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Abstract
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.
(Received May 12 1980)
Key WordsSpodoptera exempta; resource utilization; migratory drive; flight behaviour
