Jarry M., Gouteux Jean-Paul, Khaladi M. (1996). Are tsetse fly populations close to equilibrium ?. Acta Biotheoretica, 44, p. 317-333. ISSN 0001-5342.
Titre du document
Are tsetse fly populations close to equilibrium ?
Année de publication
1996
Type de document
Article
Auteurs
Jarry M., Gouteux Jean-Paul, Khaladi M.
Source
Acta Biotheoretica, 1996,
44, p. 317-333 ISSN 0001-5342
Glossina or tsetse flies, the vector of sleeping sickness, form a unique group of insect with remarkable characteristics. They are viviparous with a slow rhythm of reproduction (one larva approximately every 10 days) determined by the regular ovulation of alternate ovaries. This unusual physiology enables the age of the females to be estimated by examining the ovaries. The resulting ovarian age structure of tsetse fly populations has been used to develop research into the demography of tsetse flies. Several authors have proposed methods of estimating populations growth rates from ovarian age distribution data. However, such methods are applicable only when the growth rate (lambda) is equal to 1 (i.e. the intrinsic rate of increase r is equal to 0). In fact in this type of estimation, the adult survival rate a (or equivalently the mortality rate) cannot be dissociated from the growth rate. Other independently determined demographic parameters must be used to remove this lack of identifiability. We have built a matrix model of the dynamics of tsetse fly populations which enables the growth rate to be calculated from the pupal survival rate, the pupal period and the adult survival rate. Assuming that the age-groups of the population studied have reached a stable distribution, it is possible to calculate the probabilities for the observed sample of belonging to each of the age-groups, to construct a likewood function and thus to obtain an estimate of the "apparent survival rate" bêta = a/lambda. If the pupal survival rate and the pupal period are known, a and lambda can then be calculated from bêta. The application of this method to data collected for other two annual cycles in a savannah habitat (Burkina-Faso) showed a high overall stability in the populations of Glossina palpalis gambiensis... (D'après résumé d'auteur)
Plan de classement
Répartition et bioécologie des phlébotomes [052GLOTRY01]
Descripteurs
MALADIE DU SOMMEIL ; VECTEUR ; DYNAMIQUE DE POPULATION ; METHODOLOGIE ; VARIATION SAISONNIERE ; TAUX DE MORTALITE ; AGE PHYSIOLOGIQUE ; CHANGEMENT CLIMATIQUE
