A Method for Sexing Living Pupal and Adult Tenebrio molitor
Pupal Stage:
Figure 1: The determination of sex at the pupal stage involves observation of developing genital structures located on the ventral side just caudal to the seventh visible sternite. The female bares a larger swelling that diverges into two nipple-like papillae. On the male the swelling is considerably smaller and the papillae do not diverge or protrude much. The papillae of the male are so inconspicuous that they are easily missed. In practice the pupae sex is determined directly from the absence or presence of the large conspicuous female papillae. (Bhattacharya, A.K. and Waldbauer, G.P., 1970)
Adult Stage:
Figure 2: Determination of sex at the adult stage involves observation of the posterior ventral side of the abdomen. In the female there is little or know separation between the 3 most posterior sternites (3rd, 4th and 5th) while in the male the intersegmental membranes are clearly visible with a lighter colouring. Also, the 5th visible sternite is quite round in the male and slightly pointed in the female. (Bhattacharya, AK and Waldbauer, GP, 1970)