A NEW EXOCRINE GLAND IN NOVOMESSOR 
(HYMENOPTERA: FORMICIDAE) AND ITS POSSIBLE 
SIGNIFICANCE AS A TAXONOMIC CHARACTER 
By Bert Holldobler, Robert Stanton, and Hiltrud Engel 
Department of Biology, Harvard University, MCZ Laboratories, 
Cambridge, Mass. 02138 
Introduction 
The genus Novomessor is comprised of only three species: 
N. albisetosus, N. cockerelli and N. manni. The first two species 
are rather common in the Southwestern United Staes and North- 
ern Mexico (Creighton 1950, 1955), and the latter has been col- 
lected along the Pacific coast of Mexico (Kannowski 1954). 
The forms of Novomessor were originally described as Aphaeno- 
gaster, and recently W. L. Brown (1974) suggested that they should 
be placed back in that genus. He pointed out that “the characters 
supposed to distinguish the two genera are not very strong when 
one considers the whole world fauna of this complex”. Brown’s 
arguments were especially supported by his reexamination of 
Novomessor manni Wheeler and Creighton (1934) and Aphaeno- 
gaster ensifera Forel (1899), which he found to be synonymous. 
He concluded his reasoning by stating “. . .the example of A. ensifera 
and N. manni may help to alert myrmecologists to the kind of 
change to be expected of a worldwide reclassification. One of the 
changes in status resulting from this study is of course the return 
of cockerelli and albisetosus to their original generic assignment 
in Aphaenogaster”. 
In the course of a comparative study of communication mecha- 
nisims in Novomessor , we discovered a new complex exocrine gland. 
Since this gland is a very distinct character, it should be given con- 
siderable weight in the future taxonomic assessment of the species 
possessing it. 
Material and Methods 
Live specimens of N. albisetosus and N. cockerelli were collected 
in southern Arizona near Portal. For histological investigations the 
* Manuscript received by the editor June 15, 1976. 
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