Sarah J. Keegans

Comparative survey of abdominal gland secretions of the ant subfamily Ponerinae.

The chemical contents of three abdominal glands were investigated in representative species of the ponerine ants. The Dufour glands of 14 species show a wide variety of contents. In Mystrium camillae and Proceratium itoi, no volatile substances were found in either the Dufour or venom glands. In Ectatomma sp., Diacamma ceylonense, Diacamma indicum, Pachycondyla obscuricornis, and Pachycondyla striata, volatile chemicals were found in the venom glands as well as in the Dufour glands. Platythyrea punctata was examined, but unusually it does not have a Dufour gland and its venom gland contained no volatile substances. Epoxides were found in ants for the first time in the Dufour glands of Amblyopone reclinata. Venom glands of Pachycondyla tarsata were also found to contain volatile material, including bitter-tasting cyclic dipeptides. In all, 16 species have been added to the list of those examined. All of the 27 known analyses of Dufour glands, 21 analyses of venom glands, and 4 of pygidial glands of workers of ponerine ant species have been brought together in order to seek some pattern in the type of glandular contents. Although the great majority of species produce hydrocarbons in their worker Dufour glands, and some have terpenes, there is no observable pattern for this gland on a tribe or genus level. Volatile compounds have been found in the venom glands of some species of the tribe Ponerini only. The information on pygidial glands is still too fragmentary for any conclusions.

COMPARATIVE STUDY OF MANDIBULAR GLAND SECRETIONS OF WORKERS OF PONERINE ANTS

The chemical contents of the mandibular glands of workers of eight species of ponerine ants have been analyzed and quantified. In three species (Ectatomma sp. from Brazil, Odontomachus bauri, and Pachycondyla striata) the contents were essentially a mixture of alkylpyrazines only. Three species (Odontoponera transversa, Pachycondyla indica, and Pachycondyla obscuricornis) contained a mixture of alkylpyrazines and oxygenated compounds and some simple terpenes; and the remaining two (Diacamma vagans and a Diacamma sp. from India) had only oxygenated compounds present. The two Diacamma species were notable in containing a dioxaspiroundecane (a spiroketal), not hitherto found in ants. All the 33 known mandibular gland analyses of workers of ponerine ant species have been brought together in order to seek some pattern in the type of glandular contents. Although the majority (24 species) produce alkylpyrazines, there is no observable pattern on a tribe or genus level.

Volatile glandular secretions of three species of new world army ants,Eciton burchelli, Labidus coecus, andLabidus praedator

The Dufour glands of workers ofEciton burchelli contain a mixture of small quantities of oxygenated compounds, some of which are derived from terpenes, and C17-C25 hydrocarbons. The secretion of the Dufour glands of soldiers was either similar to that of workers, with geranylacetone a significant component, or they contained geranyllinalool in large amounts. The glands of workers and soldiers ofLabidus praedator andLabidus coecus contained (E)-β-ocimene, a new substance for the Dufour glands of ants. 4-Methyl-3-heptanone was the dominant compound in the mandibular glands ofE. burchelli andL. coecus. Skatole and indole were found in the gasters ofL. praedator, and skatole was present in the venom glands of some soldiers ofE. burchelli.

The dufour gland and the secretion placed on eggs of two species of social wasps,Liostenogaster flavolineata andParischnogaster jacobsoni (vespidae: Stenogastrinae)

The secretion placed on eggs and fed to larvae and the “ant guard” placed on the nest stalk ofParischnogaster jacobsoni contain the same hydrocarbons and in approximately the same proportions as is found in the Dufour gland. The secretion on eggs is a mixture of the contents of the Dufour gland and nectar. The emulsifying agent is a palmitic acid salt. Similarly, inLiostenogaster flavolineata, the egg secretion is an emulsion of nectar and Dufour gland secretion, which contains alkoxyethanol emulsifiers, found in nature for the first time.

The trail pheromone of the ant Crematogaster castanea

Summary.The major component of the trail pheromone of the myrmicine ant Crematogaster castanea has been identified as (R)-2-dodecanol from the tibial glands of the hind legs. The substance gave activity comparable to the contents of 8 tibial glands at a concentration of 1 pg per 32 cm trail.

What do glands tell us about species? a chemical case study of Cataglyphis ants

Abstract Chemical examination of 10 species of the genus Cataglyphis collected in Syria and Tunisia showed, in each case, that they can be readily distinguished from each other by the volatile contents of their exocrine glands. Five species of the C. bicolor group were chemically closely similar. The mandibular glands of all the species of the C. bicolor group contain 2-methyl-1-hexanol, a substance found as a natural product for the first time.

Loral volatiles of Vicia faba

Abstract The volatile odour chemical of the flowers of the field bean has been identified as ( E )-β-ocimene with only traces of other monoterpenes and an absence of esters, alcohols and other oxygenated compounds.

Chemotaxonomic study of undescribed species ofMyrmica ant from Idaho

An undescribed species ofMyrmica collected in Idaho has been shown to have the same substances in its mandibular glands (3-octanol and 3-octanone and related 3-alkanols and 3-alkanones) and in its Dufour gland (linear alkanes, alkenes, and farnesene isomers and homologs) as previously examined European species ofMyrmica. The poison gland contains the trail pheromone 3-ethyl-2,5-dimethylpyrazine, common to allMyrmica species studied so far. The Dufour gland contains large amounts of bishomofarnesene, which easily distinguishes it from some 13 otherMyrmica already known.