Fig. 2. Growth of valve apodeme during maturation is largely regulated by JH. (A) Scanning electron micrographs of the valve apodeme of females from different experimental groups. Apodemes of mature animals show increased length, width and a more complex surface structure than those of immature and allatectomised females (see also Fig. 1). By contrast, apodemes from immature or precocene-treated females are rather flat with a straight and smooth appearance. (B) Size-index values (lengthxwidth) of apodemes from immature (<5 day), mature (>14 day), allatectomised (–CA) and those females injected with the JH analog methoprene (–CA, +met). Apodemal size increases considerably between the 5th and the 14th day after adult emergence. Allatectomy markedly inhibits the increase, but replacement injections with methoprene are able to significantly reverse allatectomy effects. Data are means ± S.D.; ^***P<0.001. Scale bar in A, 1 mm; anterior is to the right.