1985] 
Sorensen, Fletcher, & Vinson — Solenopsis 
63 
dead major workers, and a dead dewinged virgin queen (Figs. 1,2,3). 
In all three trials, more virgin queens received radiolabel from the 
surface of the dead dewinged virgin queen than from the glass rod 
(F 2 ,h = 79.3, p < 0.001). In two of the trials, virgin queens received 
slightly more radiolabel from the glass rod than from the surface of 
the dead major workers (Figs. 2,3) but in one (Fig. 1), significantly 
fewer virgin queens received radiolabel from the glass rod than from 
the major workers. The location of the virgin queens in the nests 
with respect to the glass rods or dead dewinged virgin queens did 
not affect the rate of distribution of radiolabel. Significantly more 
virgin queens from the nest with the queen and treated major 
workers contained radioactivity than those taken from the second 
nest (F, 4 = 15.1, p < 0.05). 
Combining the results of the three trials, within 120 min 98% of 
the virgin queens sampled received radiolabeled egg yolk; 87% 
received radioactivity from the surface of dead dewinged virgin 
queens; 82% received radioactivity from the surface of dead major 
workers; 79% received radiolabeled albumin; 68% received radioac- 
tivity from the surface of the glass rod; 65% received radioactivity 
from the surface of a dead mated queen; and 53% received radioac- 
tivity from the surface of a live queen. All were significantly differ- 
ent (F 6 2 « = 1 27.6, p = 0.00 1 ) except for the number of virgin queens 
receiving radioactivity from either a) radiolabeled albumin or dead 
major workers and b) glass rods or dead queens. 
Role of food in pheromone transfer. 
Since 98% of the virgin queens sampled were fed radiolabeled egg 
yolk within 2 h, we examined the possibility that the presence of 
food might increase the quantity of radioactivity transferred from 
the surface of the queen to the virgin queens by encouraging food 
transfer and subsequent surface contacts among workers and 
queens. The results are given in Figure 4 as the mean number of cpm 
per virgin queen. Virgin queens tended by workers were separated 
from the queen, workers, and brood by a fine screen that permitted 
trophallaxis but restricted grooming. Only the mated queen was 
surface labeled and the distribution of radioactive tracer from I side 
to the other was dependent on trophallaxis or antennal contacts 
through the wire mesh. The virgin queens in Trial C, where food was 
