PSYCHE 
Vol. 86_December, 1979 
No. 4 
WORKER COMPATIBILITIES WITHIN AND BETWEEN 
POPULATIONS OF RHYTIDOPONERA METALLICA* 
By Caryl P. Haskins, Edna F. Haskins 
Haskins Laboratories, Inc., 
New Haven, Connecticut 06510 
Introduction 
The markedly diffuse nature of the colonial structure of Rhyti- 
doponera metallica, associated with the rarity of true females and 
the usual presence of multiple fertilized egg-laying “workers” in the 
community, blurs the spatial distinction between naturally occur¬ 
ring “colonies” to an unusual degree. This condition coupled with 
the indefinite nest-form frequently typical of the species, which com¬ 
monly occupies leaf-litter and superficial layers of soil, makes it 
difficult on occasion to distinguish a mosaic of neighboring “colo¬ 
nies” from what often superficially appears as merely a rather highly 
“viscous” population of socialized individuals. This situation lends 
special interest to the question of how far one mechanism com¬ 
monly involved in the maintenance of integrity in formicid com¬ 
munities, that of colony “identification” among workers, is 
developed in R. metallica, and, if it is developed, what may be its 
basic characteristics. This interest has led to a preliminary investiga¬ 
tion of those questions over the past several years. 
Materials and Methods 
Preliminary tests of compatibilities between workers of R. metal¬ 
lica taken from widely separated populations amply demonstrated: 
Manuscript received by the editor November 8, 1979. 
299 
