40 
Psyche 
[March 
nests was not particularly noted at first; however, when nests kept 
(without adults) in covered petri dishes were later dissected, a 
striking accumulation of fecal pellets in larval cells was noticed. 
This suggests that there is frequent contact between parent and 
offspring. Further, although the manner by which prepupae and 
pupae become uniformly secured by the anus to their cell rims is as 
yet unanswered, the possibility exists that the parents may be in- 
volved. 
Table 3. Relation between nest size and number of adult females present, 
based on 22 active night-collected nests. Parentheses indicate 
number of nests on which figures are based. 
Number of females per nest 
1 2 3 4 5 6 10 
Mean number 
of immatures 1.9(11) 1.7(3) 7.3(3) 4.0(1) 2.0(2) 9.0(1) 12.0(1) 
Reproductivity 
per female 1.9 0.8 2.4 1.0 0.4 1.5 1.2 
A nagging question in any discussion of insect sociality is whether 
division of labor exists. Significant morphological differences be- 
tween M. comes females from the same nest have yet to be found. 
No dimorphism exists in either wing length or head width. How- 
ever, this does not exclude the possibility of behavioral or physiological 
caste differences as have been found in some bees (Michener, 1958) 
and wasps (Evans, 1958). Moreover, it seems to be a general rule 
in each group of social Hymenoptera that the degree of morphological 
difference between the queen and worker castes lags behind specializa- 
tion as judged by other features. Thus, it would be especially 
valuable to know whether egg laying in the larger nests was re- 
stricted to one female or whether several females might participate. 
In nearly all of the larger colonies censused (see Table 4) one 
female exhibited a strikingly developed oocyte, in contrast to her 
nest-mates whose most developed oocytes were considerably smaller 
(less than half as long in 5 of the 8 nests). In fact, one female in 
each of four nests (5-2, 5-3, 24-1, 72-1) had two oocytes of a length 
greater than the largest oocyte to be found in any of her nest-mates. 
Thus it appears that, regardless of the number of females present 
in a colony, at any one time there is but one mature ovarial egg 
available, correlating with the earlier observation that one cell is 
provisioned at a time. More significantly, the data suggest that some 
degree of reproductive dominance (division of labor) may exist with 
one female per nest doing most of the egg laying. Data on rate 
of oocyte development and maturation would, of course, be desirable. 
