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Psyche 
[Vol. 88 
result of seed consumption by the developing larvae. I have no 
explanation for the other two peaks which appear. There is some 
evidence of a drop in seed storage in the spring in P. subnitidus, but 
it is not as great as that found in P. rugosus. Pogonomyrmex 
subnitidus also appears to begin the season with a constant amount 
of seeds, about 0.002-0.004 g/ant, much smaller quantities than P. 
rugosus. There are also many unexplained peaks in P. subnitidus 
seed storage, especially the high peak in September. Pogono- 
myrmex montanus does not store seeds in the nest. In the 
population at Big Pine Flats in the San Bernardino Mountains, we 
occasionally encountered very small caches of seeds (less than 
0.0001 g/ant) which were apparently only small daily accumulations 
of seeds that had not been eaten at that time. 
Production. 
Production in the three species is summarized in Table 4. The 
proportion of energy invested in production varies considerably 
between the three species, but in all cases it is relatively low. Total 
production constitutes 12.2, 8.3, and 7.9 per cent of the total energy 
flow in P. montanus, P. subnitidus, and P. rugosus respectively 
(MacKay 1981). In all three species, a higher percentage of the total 
production is invested in workers than reproductives (Table 4). 
Pogonomyrmex subnitidus and P. rugosus both invest heavily in 
workers, P. montanus invests heavily in reproductives. The data on 
Table 4 suggest that the three species invest more in the production 
of females than in males. The costs of respiration of males are higher 
than of females (MacKay 1981). When respiration costs are taken 
into account, the colonies of each species invest about equally in the 
production of males and females (MacKay 1981). More numbers of 
males than females are produced in all three species (Table 4). 
Individual females are more expensive to produce than are indi- 
vidual males (MacKay 1981). 
Most of the workers are replaced each year. Pogonomyrmex 
montanus colonies produce 1516 workers per year (Table 4), which 
is similar to the mean worker population of 1665 (Table 3). 
Pogonomyrmex subnitidus colonies produce 3988 workers as 
compared to a worker nest population of 5934; P. rugosus colonies 
produce 5298 workers per year compared to a worker nest 
population of 7740. 
