Fig. 3

Temperature-sensitive period of the ventral melanic abdominal pigmentation during the fifth nymphal instar of Oncopeltus. The plot shows the average normalized melanic pigmentation of adult female (a) and male (b) raised at 20 or 33 °C and transferred to 33 (dashed line) or 20 °C (solid line), respectively, on various days. The top X-axis represents the day at 33 °C when the nymphs were transferred to 20 °C. The bottom X-axis represents the day at 20 °C when the nymphs were transferred to 33 °C. The melanized area was normalized by dividing the area of the pigmented area by the total area of the A2–A4 abdominal segments. Each data point represents average calculated from measurements of 5–13 animals