Blister beetles have recently become the key pests of food crops in Mali and Senegal. The endemic areas of most destructive species, Psalydolytta fusca Oliv., P. vestita Duf., are situated in Northeast Mali and Central South Senegal. Host plants of certain species were identified. Light traps were used to study population dynamics of major species at Béma and Samé (Mali), and at Bambey, Gossas, Sokone and Nioro du rup (Senegal). Abundance of P. fusca and P. vestita populations in September–October generally coincided with sorghum and pearl millet flowering. Number of P. vestita beetles trapped was higher than that of P. fusca.