Effects of u.v. light and temperature on the melanization and the formation of daily growth layers of Sarcophaga falculata

Adult Sarcophaga flies, immediately after eclosion, were subjected to different temperature régimes or irradiated with u.v. light. The effect of the treatment on cuticular melanization was studied by comparison with specimens of control series or by comparing the areas of cuticle on the thoracic phragma of the same specimen that were deposited at different times under different conditions. The cuticle of flies that were tanned at 15 or 31°C was less melanized than that of control flies at 26°C. Irradiation with long wave u.v. light suppressed mainly the melanization whereas both the melanization and sclerotization processes were inhibited by short wave u.v. A decrease in adult melanization was caused also by exposure to u.v. of the heads of pharate adults 24 hr before eclosion.