1974] 
Jeanne F age n — Stelopolybia 
159 
Table II. Queen/Worker Dimorphism in Stelopolybia areata . 
A. Length of Alitrunk 
Colony Queens Workers Queens/ 
No. 
N 
Average 
Range 
N 
Average 
Range 
Workers 
707 
45 
4.22 
4.02-4.37 
45 
3.63 
3.29-3.75 
1.16 
710 
49 
4.10 
3.83-4.29 
60 
3.57 
3.29-3.75 
1.15 
725 
23 
4.13 
4.02-4.29 
50 
3.68 
3.41-3.83 
1.12 
731 
50 
4.19 
3.98-4.33 
50 
3.68 
3.33-3.83 
1.14 
B. Width of First Abdominal Tergite 
Colony 
No. 
N 
Queens 
Average Range 
N 
Workers 
Average Range 
Queens/ 
Workers 
707 
45 
1.60 
1.34-1.72 
45 
0.94 
0.88-1.00 
1.70 
710 
49 
1.52 
’hfO-1.68 
60 
0.95 
0.84-1.00 
1.60 
725 
23 
1.49 
1.42-1.57 
50 
0.95 
0.88-1.00 
1.57 
731 
50 
1.58 
1.42-1.76 
50 
0.93 
0.88-1.00 
1.69 
completely dimorphic with respect to this character. This is shown 
graphically in Fig. 2, where size-frequency distribution data for 
three of the colonies are grouped. (Colony 710, whose queens and 
workers are smaller than average, is omitted from Fig. 2 because its 
smallest queens overlap in size with the largest workers of two of the 
other colonies, obscuring the bimodality that exists within colonies.) 
The ratio of average length of alitrunk in queens to that in workers 
ranges from 1.12 to 1.16 for each of the four colonies sampled, with 
an overall average of 1.15. 
Allometry. The width of the first abdominal tergite is proportion- 
ately much greater in queens than in workers. This is evident in the 
large queen/worker ratios with respect to this dimension (Table II). 
The regression of the width of the first abdominal tergite on alitrunk 
length has been computed for queens and workers of each of the 
four colonies, and the equilibrium constants (k, or slope of the re- 
gression line) are presented in Table III. 
In all colonies the allometry of the worker caste is negative. For 
queens this shifts to strongly positive in all colonies except 725 (where 
small sample size may have biased the result). The intranidal dif- 
ferences in k for queens and workers are significant at the 1% level 
