TRAIL COMMUNICATION IN THE DACETINE ANT 
ORECTOGNATHUS VERSICOLOR 
(HYMENOPTERA: FORMICIDAE)* 
By Bert Holldobler 
Department of Organismic and Evolutionary Biology, 
Harvard University, Cambridge, Mass. 02138 
Although division of labor within two dacetine species has been 
studied at length (Wilson 1962; Carlin 1982), very little has hitherto 
been reported on social communication in the Dacetini, a myrmi- 
cine tribe of nearly 200 known species (Brown and Wilson 1959; 
Wilson 1962). Foraging habits have also been studied in several 
species (for review see Brown and Wilson 1959; Wilson 1962). As 
now known, the dacetines seem to be individual foragers; recruit- 
ment to food sources and cooperation during retrieval of prey have 
not been observed. It is therefore of some interest that we have 
recently discovered trail laying and trail following in the dacetine 
species Orectognathus versicolor. Experiments in the laboratory 
further indicate that trail communication may play an especially 
important role during nest emigrations. 
Material and Methods: 
A queenright colony of O. versicolor was collected from rotting 
wood near Eungella, North Queensland (Australia) and housed in a 
glass tube (</> 1 cm), with water trapped at its bottom behind a 
cotton plug. The nest tube was laced into an arena (45 X 30 cm) in 
which small pieces of cockroaches ( Nauphoeta cinerea), chopped 
meal worms ( Tenebrio molitor ), several species of small flies and 
honey water were provided as food. The colony developed very well 
under these conditions, and when the experiments began (4 weeks 
after collection) it contained one queen, 80 workers (42 minors, 27 
medias, 11 majors (see Carlin, 1982)), 14 freshly eclosed males, and 
brood of all stages. 
For histological investigations live specimens were fixed in Car- 
noy (Romeis 1948), embedded in methyl-methacrylate and sectioned 
8 fj, thick with a Jung Tetrander I microtome (Rathmayer 1962). The 
♦Manuscript received by the editor December 1, 1981. 
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