Titre :
|
Population regulation in aphids
|
Auteurs :
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A. Dixon ;
P. Kindlmann ;
R. Sequeira ;
A. Dixon, - Editeur scientifique ;
P. Kindlmann, - Editeur scientifique ;
R. Sequeira, - Editeur scientifique
|
Type de document :
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article/chapitre/communication
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Année de publication :
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1996
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Format :
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103-114
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Langues:
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= Anglais
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Mots-clés:
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population regulation
;
time series analysis
;
individual based model
;
aphids
;
Myzocallis boerneri
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Résumé :
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Recent analyses of aphid population dynamics have used yearly totals of the suction trap catches of aphids, but it is questionable whether such analyses reveal anything more than that aerial numbers are regulated in some way. The numbers of the host specific Turkey-oak aphid, Myzocallis boerneri, on two Quercus cerris trees have been monitored weekly for 18 years. This census data was analysed to determine the nature of the density dependence and the time scale over which it operated. In addition, an individual based simulation model was developed for the aphid and used to identify possible mechanisms of regulation. The partial autocorrelation function (PACF) plots of seasonally adjusted data revealed that aphid abundance is regulated by First-order density dependent processes acting over a time frame of a month or less. A correlation matrix also confirmed that the spring and autumn increases and the numbers overwintering are predictable, but not the extent of the summer decline. The model was used to predict seasonal population trends. The output very closely matched the empirical data, suggesting that the regulatory process is intraspecific competition for resources, causing an immediate size related reduction in recruitment and increase in the tendency to migrate. The correlation matrix indicated a negative correlation between the numbers in July and those next spring. The negative correlation between the numbers of First generation in spring and the last generation in autumn, observed in other tree-dwelling aphids, is weak or not present in this species.
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Source :
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Frontiers of Population Ecology - 0-643-05781-1
|