Chemical investigations of insect exocrine glands

Abstract

The trail-following component of the trail pheromone of Pheldole pallidal a has been identified as a 3-ethy1-2,5-dimethylpyraz1ne. It is present in minor but not major workers. Another component which acts as primer appears to be required but it has not been identified.
A time study of the filling of the Dufour gland of Formica sanquinea from emergence of adults for several months has shown the gland fills slowly and the composition changes with time. A re-examination of the mandibular gland secretion of Tetramorlum caespitum has shown It contains chiefly 4-methyl-3-hexano1 not 3-octanone.
The Dufour glands of workers and queens of the myrmicine ants Leptothorax acervorum and Messor minor and the formicine ant Camponotus aethlops have shown little differences between the castes. Dufour glands of workers of the myrmicine species leptothorax nylanderi. Hessor capltatus, T. caespitum. Myrmica lonae. Myrmica sabuleti, Hyrmlca aloba. and Hyrmica scabrinodls. and the formicine species Formica fusca. Formica lemani, Lasius fullqlnosus, Camponotus aeqyptiacus. Camponotus vagus and Cataglyphis saviqnyl have been carried out. Examination of caespitum from a wide range of habitats has shown no significant differences In composition. For F. fusca and F. lemani. the substances of the Dufour gland enable the species to be distinguished chemically. Attempts to use Dufour gland substances to distinguish between a group of uncertain Hyrmlca species was inconclusive. The Dufour glands of major and minor workers of C. aegyptlacus have quite different composition, the former contain acetates in quantity.
Attempts to study the sexual pheromone of the beetle Attaqenus scalarls were frustrated by the inability to aaintain live insects. Hexadecanoic acid, octadecano1c ac1d and octadecenoic acid were 1dent1f1ed in the body 1n sign1f1cant quant1t1es and w1ll have to be tested to see if they prov1de the pheromone.