Juvenile hormone (JH III) is an important example of a chemical signaling derived from the terpene biosynthetic pathway. Because of its impact on many species’ reproductive and developmental processes, analytical approaches must be developed to accurately identify and measure it in biological samples. In this technical note, we explored the gas-phase dissociative behavior of JH III using tandem mass spectrometry combined with electrospray ionization to provide diagnostic fragment-ions for quantitative purposes.

Abstract The social wasps have a remarkable system of organization in which chemical communication mediate different behavioral interactions. Among the compounds involved in this process, cuticular hydrocarbons are considered the main signals for nestmate recognition, caste differentiation, and fertility communication. The aims of this study were to describe the cuticular chemical compounds of the species Mischocyttarus consimilis, Mischocyttarus bertonii, and Mischocyttarus latior, and to test whether these chemical compounds could be used to evaluate differences and similarities between Mischocyttarus species, using gas chromatography coupled to mass spectrometry (GC-MS). Workers from these three species presented a variety of hydrocarbons ranging from C17 to C37, and among the compounds identified, the most representative were branched alkanes, linear alkanes and alkenes. The results revealed quantitative and qualitative differences among the hydrocarbon profiles, as confirmed by discriminant analysis. This study supports the hypothesis that cuticular chemical profiles can be used as parameters to identify interspecific and intercolony differences in Mischocyttarus, highlighting the importance of these compounds for differentiation of species and populations.

ABSTRACT In leafcutter ants the division of labour is associated to worker size variation clustered in four subcastes. In this work we used Atta sexdens Forel (1908) as a model to test the hypothesis that each subcaste expresses its own chemical signature comprised of cuticular lipids. To assess it, we extracted epicuticular compounds by using nonpolar solvent hexane and analysed the samples in a combined Gas Chromatography-Mass Spectrometer (GC-MS). We found 24 hydrocarbons with carbon chains ranging from 19 to 39 atoms most of them classified as linear and branched alkanes. No compound occurred in the cuticle of specific worker subcaste, however, the relative proportion pattern varied greatly among them. Our results suggest that although subcastes have similar chemical signatures, significant differences in their relative proportions may play an important role between nestmate and group identification.