1972] 
McCluskey & Brown — Paraponera 
339 
between the mandibles of one ant after 40 min, from another at 1 
hr, and from the final one at 2 hr. Each of the three samples was 
chromatographed on a paper strip. Only sucrose could be detected, 
indicating that there had been no digestion. 
Rhythms in Room Conditions 
The main laboratory lights were on from 0800 to 2000. There 
was very dim artificial light in the distance during the night. The 
temperature of the laboratory was relatively stable (25-30°C). 
The whole box including the nest chamber was darkened, and a 
tube led to an arena box of equal size exposed to the light-dark cycle. 
Figure 2 shows the number of workers at each time of day in the 
arena and in the nest chamber. Also plotted is the level of activity 
(“activity index”) at each observation. Both the number in the 
arena and the level of activity reached a peak twice a day: just be- 
fore the lights came on (a little light entered around the window 
shades for an hour or two before the lights came on), and during 
the last hour before the lights went off. At the times of peak num- 
ber out in the arena, the ants were also the most active, running 
about the box and even jumping — a striking sight. 
For comparison is shown the prominent rhythm of appearance out- 
side the nest of male Argentine ants, Iridomyrmex humilis. They 
were from a colony of Wilson’s elsewhere in the same room on the 
same days. Males of this species come out only during the last of 
the light period, as previously shown for another colony (McClus- 
key, 1958). 
Rhythms in Controlled Conditions 
Some of the ants were transferred to a darkroom for observation in 
constant temperature (Feb. 3-Mar. 11, 27 0 dz i°C; Mar. 12-Apr. I, 
28° ± i°C) and more completely controlled lighting. There was 
fluorescent light, 400 lux, for 12 hours daily; clear ruby light dur- 
Fig. 2. Worker rhythms, room conditions (also, at top of figure, Iridomyr- 
mex male rhythms elsewhere in same room). One nest containing 50 
Paraponera workers. Means ± SE are based on 3-5 days (Feb. 4-19) for 
Activity Index, and on 3-8 days (Feb. 3-19) for No. in Arena or Chamber 
(3-5 days, Feb. 4-18, for Iridomyrmex ) . ANOVA’s give P<.001 for each 
rhythm shown. To give a more complete picture, first count after mid- 
night is repeated in each case. “Dawn” (solid) and “dusk” (dashed) lines 
show when room lights were turned on and off. Activity Index: 4, very 
active or jumping; 3, active; 2, moderate; 1, fairly slow; 0, slow or quiet 
(“intense” includes only levels 4 and 3). 
