The chemistry of the metasternal gland secretion of the eucalypt longicorn Phoracantha synonyma (Coleoptera : Cerambycidae)

The metasternal gland secretion of Phoracantha synonyma contains a diversity of volatile components, one of which, 2-hydroxy-6-methylbenzaldehyde (1), is of widespread occurrence in the genus. Threemajor components and several minor components are macrocyclic lactones, of which the following have been positively identified: decan-9-olide (2), (2)-dec-4-en-9-olide (3) and 11-hydroxytetradec-5-en-13-olide (4). The methyl and ethyl esters of 2-methylbutyric and related acids are also present and are responsible for the characteristic odour of the fresh secretion.

Chemistry of the metasternal gland secretion of the common eucalypt longicorn, Phoracantha semipunctata (Coleoptera: Cerambycidae)

The metasternal gland secretion of Phoracantha semipunctata contains five significant volatile components, of which the most abundant is 2-hydroxy-6-methyl-benzaldehyde (1). The second most abundant component, which has been named phoraoanthol, has been shown by synthesis to be (5-ethylcyclopent-1-enyl)methanol (2). The three other components are aldehydes, derivable from phoracanthol and cis- and trans-dihydrophoracanthols, respectively. Apparently all five components are related biosynthetically.