1988] 
Hare — Marking ant larvae 
303 
In the series of simultaneous presentations neither L. ambiguus 
nor L. longispinosus worker groups showed a significant preference 
for retrieving marked or unmarked larvae (T=32.5, P>0.50 and 
T=37, P>0.50 for L. ambiguus and L. longispinosus respectively). 
An average of 4.7 + 0.77 (mean + lSE) marked and 4.3 + 0.52 
unmarked larvae were retrieved first by the 16 L. ambiguus groups 
while 4.3 + 0.49 marked and 3.6 + 0.51 unmarked larvae were re- 
trieved first by the 13 L. longispinosus worker groups (Fig. 1, day 0). 
Furthermore, the number of groups accepting a greater number of 
marked larvae; unmarked larvae, or equivalent numbers of both 
types in paired presentations (Table I) was similar across the two 
species (3X2 contingency table analysis (Zar 1974), x 2 = 1.1659, 
P>0.25). 
For both L. ambiguus and L. longispinosus, the data from indi- 
vidual worker groups were homogeneous on each day of observa- 
tion and no significant preference for either marked or unmarked 
larvae was shown by any single group over the course of the study 
(all P>. 25, see Appendix B-l in Hare, 1987). Similarly, no signifi- 
cant differences in the number of marked and unmarked larvae 
remaining in the nests of either species were detected when data 
were pooled by day (all P>.50, see Appendix B-l in Hare, 1987). 
The mean numbers of marked and unmarked larvae accepted by 
worker groups on any given day were similar, although at almost all 
time intervals the average number of marked larvae per nest was 
slightly higher than that for unmarked larvae (Fig. 1). 
The large increase in the mean number of marked and unmarked 
larvae accepted for groups of both species between day 0 and day 1 
reflects the fact that the day 0 data include only those larvae 
retrieved first in the series of paired presentations. Following this 
series of presentations, ‘non-preferred’ larvae were re-introduced 
and overall, 99.3% of the marked larvae and 97.2% of the unmarked 
larvae available to the L. ambiguus worker groups were accepted by 
day 1 while 98.3% of the marked larvae and 100% of the unmarked 
larvae available were accepted by L. longispinosus worker groups 
during the same period. Thus, even those larvae that were ‘non- 
preferred’ in a simultaneous choice situation were acceptable to 
Leptothorax workers. 
The increase in the mean number of marked larvae in the L. 
longispinosus nests between days 14 and 15 (Fig. 1) is a result of the 
