Fig. 4. Ontogeny of cuticular hydrocarbons of various chain lengths during the first 2 days of imaginal life following a heat shock 3 h after AE. Hydrocarbons were pooled according to the length of their carbon chain (23C-33C). The hydrocarbons usually secreted by immature flies range from 29C-33C (broken lines), whereas the CHs produced by mature flies mostly have 23C-29C (solid lines). Experimental (+HS) and control (no HS) flies are males (A) and females (B) from the hsp70-GAL4 x UAS-tra (hsp-tra) genotype. Values are means of absolute amounts (ng) ± S.E.M. of pooled CHs after extraction in 6-48 h-old flies (age is given as h after AE). For each data point, N=8-10.