INTRASPECIFIC AND INTERSPECIFIC VARIATIONS IN THE DEFENSE SECRETIONS OF THE MALAYSIAN TERMITE HOSPITALITERMES (ISOPTERA, NASUTITERMITINAE)

Chemotaxonomic studies on five species of Malaysian Hospitalitermes viz. H. bicolor, H. flaviventris, H. hospitalis, H. umbrinus and H. species A have revealed distinctive interspecific differences in their defence secretions. Additionally, H. umbrinus showed unique intraspecific variations that enable it to be separated into two distinct chemotypes on the basis of marked differences in the structures of diterpenes. One chemotype produces mainly the common tricyclic trinervita-1 (15),8(19)-dien 2-beta, 3-alpha-diol while the other from both sympatric and allopatric colonies gives highly oxygenated trinervitadiene propionate esters, some of which contain a new C-17 methylated tricyclic skeleton. NMR and MS data have indicated that one of the diterpenes has this novel structure as well as being the diterpene with the highest reported molecular weight (mol. wt 736). Discriminant analysis of the data showed that mono- and diterpenes were useful for differentiating among the species. Genetic distance calculations based on these compounds showed that H. bicolor was distinct from the other species.