326 
Psyche 
[Vol. 91 
Table 1. Mean amount of food (ug) contained by foragers (F), reserves (R), nurses 
(N), queens, and larvae in various tretment combinations. Least square means and 
standard error in parentheses are given using the amount of food per colony as a 
covariate. 
Subcaste 
F/R' 
F/N 
R/N 
F 
N 
R 
F/N/R 
Foragers 
2.8a 
2.0b 
— 
2.5a 
— 
— 
1.5b 
(0.8) 
(0.3) 
(0.3) 
(0.3) 
Reserves 
2.3a 
— 
0.9b 
— 
— 
1.1b 
0.8b 
(0.2) 
(0.2) 
(0.2) 
(0.1) 
Nurses 
— 
0.9a 
0.9a 
— 
0.6b 
— 
0.7b 
(0.1) 
(0.1) 
(0.1) 
(0.1) 
Queens 
2.0b 
5.3a 
0.8b 
6.1a 
0.8b 
1.5b 
4.4b 
(1.2) 
(1.2) 
(1.2) 
(L2) 
(L6) 
(1.2) 
(0.8) 
Larvae 
1 7.9c 
39.9ab 
42.3ab 
32.1b 
42. lab 
35.6ab 
43.8a 
(4.3) 
(4.4) 
(4.2) 
(4.3) 
(5.2) 
(4.3) 
(2.9) 
a. Least square means followed by different letters are significantly different at p < 
0.05 for each subcaste group. Larvae were measured together, 50 larvae per 
measurement. 
than queens tended by other worker groups. Foragers paired with 
reserves or by themselves accumulated significantly more food than 
foragers paired with nurses or with nurses and reserves. Nurses 
received significantly more food when paired with either foragers or 
reserves than when paired with both foragers and reserves or left 
alone as a group. Reserves accumulated significantly more food 
when paired with foragers than when by themselves, paired with 
nurses, or held with both nurses and foragers. 
When we observed marked nurses, we again saw a 3 day delay 
before any nurses entered the foraging chamber and only 10% of the 
nurses were foraging after one week (data not shown). When 
reserves and foragers were added, none of the marked nurse/ 
foragers returned to the brood chamber but remained on the nest 
periphery and at least 50% of them actively foraged for food. When 
isolated with brood, 50-60% of the foragers remained with the 
larvae and did not forage (data not shown). When nurses and 
reserves were added, only 5-10% of these marked forager/ nurses 
remained with the brood, 70% returned to the nest periphery, and 
20% actively foraged for food. 
