Metapleural‐ and Postpharyngeal‐Gland Secretions from Workers of the Ants Solenopsis invicta and S. geminata

Abstract

Chemical analyses by GC-MS of the metapleural glands (MG) from workers of Solenopsis invicta and S. geminata revealed for the first time the chemical composition of these glands and showed small differences between the two species. The MG of both species contain oleic, stearic, linoleic, and palmitic acid. Both ants, in addition, have small but significant amounts of hydrocarbons in their MG reservoir, which are the same as those found in their postpharyngeal glands (PPG). The PPG of both species contain alkanes, alkenes, and Me-branched alkanes. Each species is characterized by a specific composition of PPG chemicals with some overlap between species. These results suggest that the MG synthesizes mainly palmitic, linoleic, oleic, and stearic acids in these two ants, whereas PPG contains hydrocarbon mixes that widely vary between these two phylogenetically related species.

Venom Alkaloid and Cuticular Hydrocarbon Profiles Are Associated with Social Organization, Queen Fertility Status, and Queen Genotype in the Fire Ant Solenopsis invicta

“…All castes possessed the typical hydrocarbons found in previous studies (e.g., Cabrera et al 2004). However, we also found additional unsaturated compounds not previously reported (Fig.…”

Ant Interactions with Soil Organisms and Associated Semiochemicals

“…The metapleural gland chemistry of Solenopsis invicta and S. geminata has been reported as a series of four fatty acids: palmitic, linoleic, oleic, and stearic acids, along with minor amounts of hydrocarbons, which are attributed to substances (cuticular hydrocarbons) accumulating in the MG reservoir from the cuticle (Cabrera et al 2004). Although neither MG extracts nor their individual components have been evaluated for antibiotic activity at physiological concentrations, some fatty acids do negatively impact bacteria (Kabara et al 1972).…”

“…Although neither MG extracts nor their individual components have been evaluated for antibiotic activity at physiological concentrations, some fatty acids do negatively impact bacteria (Kabara et al 1972). When minimum inhibitory concentrations from Kabara et al (1972) are compared with the amount of each of the four carboxylic acids found by Cabrera et al (2004), it is clear that one (S. geminata) or two of the acids (S. invicta) are at a concentration high enough to inhibit bacterial growth (Table 2), especially since the MG reservoir volume is likely much less than 1 μl. The hypertrophied MG reservoir volume for Crematogaster inflata is about 0.1 μl (data in Billen et al 2011).…”

“…Carboxylic acid Minimum Inhibitory Concentrations (MIC) for 8 bacteria species and 2 strains(Kabara et al 1972) compared with the amount of four carboxylic acids found in S. geminata and S. invicta MGs(Cabrera et al 2004). NI 0 Not Inhibitory…”

Intraspecific and Intracolonial Variation in the Profile of Venom Alkaloids and Cuticular Hydrocarbons of the Fire AntSolenopsis saevissimaSmith (Hymenoptera: Formicidae)

“…Cuticular hydrocarbons proved useful in separating between similar species in other difficult groups of ants [8,9], and the profiles of cuticular hydrocarbons of some Solenopsis species have already been determined [10][11][12][13]. The use of relative amounts of venom alkaloids-currently credited to be species specific-has also been proposed [8,14].…”