(A) Met knockdown efficiency and VgA mRNA levels in the fat body of the dsGFP control (iGFP), Met RNAi (iMet), and iMet further treated with methoprene for 48 h (iMet+JHA). **, P<0.01 and ***, P<0.001; n.s, no significant difference; n = 4–6. (B) Fat body cell ploidy (a–f) and DNA synthesis (g–i) of iGFP, iMet and iMet+JHA. Blue, nuclei; green, F-actin; red, de novo DNA synthesis. Enlarged images (4×) of a–c are shown in d–f, respectively with the white bar, 20 µm and red bar, 5 µm. (C) Statistical analysis for the diameter of cell nuclei. **, P<0.001; n = 80–100. (D) FACS analysis of DNA contents in fat body cells. (E) Representative phenotypes of ovaries and ovarioles after iMet, iMet+JHA vs. iGFP. (F) Statistical analysis for length*width index of primary oocytes. ***, P<0.001; n = 30.