Activité Saisonnière de vol des Pucerons [Hom. Aphididae] Dans l'Ouest de la France. Résultats de Neuf Années de Piégeage (1967-1975)

Abstract

SummaryY. Robert & Joëlle Rouzé-Jouan: Seasonal flight activity of aphids (Hom. Aphididae) in the West of France: results of nine years of trapping (1967-1975).A yellow water-filled square tray was operated for nine years in Rennes to get informations about the seasonal occurence, diversity and flight activity of aphids in the West of France. More than a hundred of species were trapped, of which sixteen were choosen as being representative of the different trends of flight activity.When all aphids are involved, bimodal curves of flight activity are obtained during the whole year, with peak occurence in may-july and october (fig. 1). The annual diversity index of Williams varies from 11,5 to 15,5 from one year to the other but fluctuates within each year, reaching a maximum at about the beginning of june and a low value during autumn (fig. 2).When individual species are now considered, many types of flight patterns can be set out: some species such as B. brassicae, M. persicae, A. fabae show a double seasonal peak occurence in spring/summer and autumn (fig. 3), others, only a spring (C. aegopodii), a spring/summer (T. annulatus) or an autumn one (R. padi) (fig. 4), many transition types (fig. 5 and 6) or even lack of typical pattern (A. corni) being possible.A quantitative biennial alternation in the catches of some « monomodal » species such as C. aegopodii, T. annulatus, can be observed and a provisional classification of species showing the same balance in the catches between spring/summer and autumn in the same year is proposed (fig. 7). Such similar quantitative seasonal reactions between species and years, although they might be fortuitous, may be useful, though, for future work concerned with causal interpretation of the data presented here and actually already undertaken.