RHYTHM VARIABLES AS 
TAXONOMIC CHARACTERS IN ANTS 
By Elwood S. McCluskey 1 and Siu-Ming A. Soong 2 
Loma Linda University, Loma Linda, Ca 92350 
A survey of many species of ants in the field indicates a generic 
difference in the hours of flight and of worker aboveground activity 
(McCluskey 1973, 1974). Further, species within the same genus 
may differ consistently (Holldobler 1976; Levieux 1977; Whitford 
and Ettershank 1975). Would the same be true if the habitats of the 
various species were made identical? The present paper reports a 
beginning laboratory test of this question in worker ants. Secondly, 
it uses multivariate analysis to examine rhythm and other 
laboratory-type variables for their potential as taxonomic charac¬ 
ters. A preliminary report was given by McCluskey and Soong 
Methods and Materials 
The species observed were: Pogonomyrmex califomieus (Buck- 
ley), Pogonomyrmex rugosus Emery, Veromessor andrei (Mayr), 
and Veromessorpergandei (Mayr) in the tribe Myrmicini of Myrmi- 
cinae; and Formica pilicornis Emery and Myrmecocystus mimicus 
Wheeler in the tribe Formicini of Formicinae. The ants were all 
collected May 24 and 25, 1973, near Loma Linda or Colton, San 
Bernardino County, California, at an elevation of about 350 m. 
Each group of ants was placed in a clear plastic refrigerator dish 9 
cm in diameter by 3 cm deep. Sugar water was provided by a cotton- 
plugged tube hanging down through the lid, and constant moisture 
by a wick of dental cotton projecting up from water in a like dish 
nested underneath. A clear plastic (Tygon) tube 8 cm long led to a 
dish of the same type to serve as a dry arena. The nest dish was 
totally covered by heavy black paper, while the tube and arena were 
fully exposed to the light. 
'Departments of Biology and Physiology; address for reprints. 
department of Biology; present address, 550 Victoria Road, Baguio Villa, Block 46 
3F. Hong Kong. 
Manuscript received by the editor July 5, 1979. 
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