New Alkaloids in the Venoms of Fire Ants

2 piperidine alkaloids of lower molecular weight are reported as the sole components in the venom of a Solenopsis population (new species to be described elsewhere) from Brazil, and as minor constituents in those of alate females of both S. geminata and S. richteri from the United States.

Abstract

A recent comparative analysis of the venom components of 4 species of fire ants (Solenopsis geminata [F], S. invicta Buren, S. richteri Forel, and S. xyloni MacCook) has demonstrated that their alkaloidal compositions may be of some taxonomic utility (Brand et al. 1972). In addition, although the chromatographic patterns may vary quantitatively in detail among individuals in a nest, pooled venom samples of the same species, even from widely separated sites, are very similar. As part of our continuing studies of the alkaloidal components of the venoms of various Solenopsis species, we have examined venom samples from a large number of Neotropical species. We plan to compare our gas-liquid-chromatographic (GLC) data for these venom samples with the taxonomy of these same populations as reflected in morphological characters; these chemotaxonomic aspects of this work will be reported later. Generally speaking, the components of all venoms so far investigated exhibit the same molecular weight range as do those from the venom of S. invicta (MacConnell et al. 1971); that is, side chains of 11, 13, and 15 carbon atoms at the 6-position of a 2-methyl-substituted piperidine. In this paper, however, we report 2 piperidine alkaloids of lower molecular weight as the sole components in the venom of a Solenopsis population (new species to be described elsewhere) from Brazil, and as minor constituents in those of alate females of both S. geminata and S. richteri from the United States.