Biology of sweet potato weevil, Cylas formicarius F. on sweet potato

The life stages of Cylas formicarius in sweet potato tubers were assessed during first and second generations. In first generation, the highest egg period was recorded in Co-3 (White) (5.50 days). The lowest larval period was recorded in Kanjangad (24.16 days) while highest pupal period was recorded in Kanaka (Red) (7.56 days) and the total life cycle period in days was highest in Co-3 (White) (42.49 days) whereas the lowest mean life cycle period was recorded in Kanjangad (red) (33.59 days). In the second generation, the highest egg period was recorded in Co-3 (White) (5.80 days), lowest larval period was recorded in Villupuram local (red) (25.34 days). The highest pupal period was recorded in Kanaka (red) (7.89 days). The highest total life cycle period was recorded in Co-3 (White) (43.67 days) and lowest total life cycle period was recorded in Villupuram local (red) (35.40 days).