Expression of Scr in Blattella germanica and RNAi effects. (a) mRNA levels of Scr in the three thoracic segments, prothorax (T1), mesothorax (T2) and metathorax (T3), and in the 2nd and 3rd abdominal segments (A2–3) of female nymphs, measured on day 6 of sixth (last) instar (N6D6). (b) mRNA levels of Scr during N6 in T1. (c) mRNA levels of Scr measured in T1 on N6D6 in controls (dsMock-treated) and dsScr-treated insects; female nymphs were treated with three 2 µg doses of dsRNA, the first injected in freshly emerged fourth instar (N4D0), the second in N5D0 and the third in N6D0. (d) Dorsal view of the pronotum of adult females from the control (dsMock-treated, n = 23) and dsScr-treated groups (n = 51), including examples of mild, moderate and severe effects. Expression (a–c) is represented as mRNA copies per 1000 copies of actin-5c (mean ± s.e.m., n = 4). In (c), expression is normalized against respective control values (indicated as 1) and the asterisk indicates statistically significant differences with respect to controls (p < 0.05), according to REST [28].