Acrida (1974) 3, 1-5

S.D. Gillett (1974)
Density and numbers in locust social aggregation
[Influence de la densité et du nombre des acridiens sur leur agrégation sociale]
Acrida 3, 1-5
Abstract: The grouping behaviour of second-instar nymphs and adults of Schistocerca gregaria (Forskal) that have been reared crowded maybe modified by available space, by density of individuals and by numbers present.
Locusts were placed in arenas of different sizes and their grouping behaviour studied. When more space was made available to a constant number of locusts, nymphs maintained their level of grouping whereas adults showed some fall-off in grouping as individuals spread-out.
Increasing the number of locusts present in a constant area resulted in a marked increase in the level of grouping for both nymphs and adults. It was shown that, for nymphs at least, this increase in grouping was not just a consequence of increased density but was also influenced by the increase in absolute numbers of nymphs present.

Une augmentation du nombre des Criquets dans un espace limité renforce la tendance à 1'aggrégation; par contre, le fait d'agrandir l'espace disponible n'entraîne pas forcément une diminution de cette tendance. Pour une densité constante mais avec une augmentation du nombre total des insectes, on observe une tendance à l'aggrégation plus forte chez les larves mais non chez les imagos.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Schistocerca gregaria