Mature larvae usually leaves the victim or the back of the leaves, petioles, veins and weeds on a thin silk cocoon so pupation, pupal stage 5-15 days.

• 老熟幼虫一般在被害叶片背面或枯叶、叶柄、叶脉及杂草上吐丝做薄茧化蛹，蛹期5-15天。