Variabilité géographique et sélection du caractère durée de développement chez Agrotis segetum
Auteurs : Buès (Robert), Poitout (Henri Serge) et Toubon (Jean-François)
Année de publication : 1989
Publication : Entomologia experimentalis et applicata
Volume :
50
Fascicule : 2
Pagination : 101-111
Résumé :
The adaptation of Agrotis segetum Schiff. (Lep. Noctuidae) in various geographic zones of its distribution area, depends upon the variability of biological characters (development time and pupation thermal threshold). The existence of a latitude gradient linked to the variation of these characters is shown. The latter should allow overwintering of the species during its last larval stage and ensure better survival. Laboratory-conducted selection experiments show that these characters are heritable. Selection pressure, when exerted on a single character (long or short development time at 25.degree. LD 12:12), leads to repercussion on others as well, agreeing with the variations observed in the natural populations. It is thus possible, from a Paris area population, to select strains exhibiting the characteristics of natural populations from the South of France, or from the Northern limit of A. segetum. These results are considered within the general context of life cycle adjustment, in terms of geographical zones