Identification of Juvenile Hormone 3 as the Only JH Homolog in All Developmental Stages of the Honey Bee

Total extracts from worker larvae, pupae, and adults of the honey bee were analyzed for their juvenile hormone contents. Using the 10-(heptafluorobutyrate)-ll-methoxy derivative, the hormone was isolated in yields of 20 — 50% in nanogram quantities as calculated from isotope dilution and from gas chromatography with electron capture detection. The procedure is sensitive enough to isolate the juvenile hormone out of 1 — 4 grams insect material for qualitative and quanti­ tative analysis. Only juvenile hormone 3 (methyl 10.11-epoxy-2-fr<ms, 6 -irares-farnesoate) could be detected as the predominant hormone homolog of all the three developmental stages. Juvenile hormone 1 (methyl 3.11-dimethyl-10.11-cis-epoxy-7-ethyl-2-£r<ms, 6 -frans-tridecadienoate) could, if at all, only be identified in trace amounts, and juvenile hormone 2 was completely absent in all stages. This first systematic analysis of a hymenopteran insect shows a modulation of JH3 titre between zero and 2 ng per gram body weight during imaginal development and a rather constant JH3 titre near 10 ng per gram in the adult.