Temporal and spatial distribution of the main Lepidoptera in Tadla

Population dynamics of sorne Lepidoptera species has been monitored by means of adult sex and light pitfalls during 2 years in 2 sites. There are 3 kinds of Lepidoptera : the pests, the less harmfull and those of no harm for agriculture. Different Lepidoptera colonize the field through a weIl adapted calendar for a better exploitation according to the species behavior and adaptability and to climate conditions. These conditions impact on pitfall efficiency has been discussed. Spodoptera littoralis, Agrotis segetum and Earias insulana appear in MarchApril and disapear in October-November. Heliothis armigera activity period is shorter ; it spreads from June to October, while Vanessa cardui was active during Automn and spring. These Lepidopteran polyphagy and the polycrop present system are favoring generation overlapping. This biological data has to be considered in an actual biological control against these noctual Lepidoptera.

Key words: Egg parasitoïd -Population dynamic Spodoptera littoralis -Heliothis armigera -Agrotis segetum -Earias insulana -Vanessa cardui -Nutritional adaptability -Generation ovelapping - Tadla