Detection of [formula omitted] JH III in several life-stages of [formula omitted] and [formula omitted

Abstract

We have conducted a reinvestigation into both the identification and quantification of juvenile hormone (JH) from several developmental stages of the cockroach, Nauphoeta cinerea , and the firebrat, Thermobia domestica , using a gas chromatography-mass spectrometric (GC/MS) method. We detected only JH III in these animals in contrast to prior studies in which JH I, II, and/or III had been reported using a different scheme relying on HPLC purification and subsequent GC/MS analysis under chemical ionization (CI) conditions. Very high levels (∼800 ng/g) of JH III were found in N. cinerea embryos at stages after dorsal closure whereas first stadium nymphs and female penultimate stadium nymphs contained only low levels (∼1 ng/g and ∼7 ng/ml respectively); in adult females at the stage of rapid oocyte growth ∼150 ng JH III per ml of hemolymph was measured. T. domestica nymphs and egg laying adults contained only low levels (∼1 ng/g) of JH III. The results emphasize the caution which must be used in interpreting results of procedures for analysis of JH at parts-per-billion levels, and also enforce prior observations that the higher JH homologs are not present except in the Lepidoptera .