1984] 
Frank — Fig w asps 
291 
logical or behavioral differences relevant to pollination were noticed 
between the two species studied, the descriptions that follow apply 
to both fig wasp species. 
Observations 
The details of the flowering and pollination cycle of Ficus citrifo- 
lia and F. aurea will be described in this section. The cycle is pres- 
ented according to the stages of development of the fig inflorescence 
(syconium). 
Early Development of Syconium and Entry by Pollinator Wasps 
A monoecious syconium is a globular inflorescence containing 
hundreds of pistillate and fewer staminate florets that line a sealed 
cavity. The only entrance into this cavity is a series of closely 
packed, overlapping scales called the ‘ostiole.’ The young syconia 
first appear singly, or in pairs, as small protrusions in the leaf axils. 
Syconia of F. citrifolia develop a peduncle 0.5- 1.5 mm long, while 
syconia of F. aurea are sessile and subtended by basal bracts. Dur- 
ing the early stages of syconium development, the ostiole of F. aurea 
is hidden by two bracts that envelop the entire syconium, while 
ostiolar scales of F. citrifolia are exposed but remain tightly packed, 
thereby preventing entry by the wasps. As the pistillate florets in 
the syconia mature, the ostiolar scales of F. citrifolia loosen, and the 
enveloping bracts of F. aurea spread to reveal the ostioles. At this 
stage syconia of F. citrifolia are 5-8 mm in diameter, and syconia of 
F. aurea are 4-6 mm in diameter. The syconia are now ready to be 
entered by the pollinator wasps. Circumstantial evidence suggests 
that the trees emit a species-specific chemical attractant that indi- 
cates receptive syconia (Frank 1983a). Experimental evidence sug- 
gests that the pollinator wasps Pegoscapus assuetus (reared from F. 
citrifolia) and P. jimenezi (reared from F. aurea) distinguish 
between the two fig tree species and, except for rare events, will only 
enter their own host tree species (Frank 1983a). 
The wasps’ entry into the syconia is a fixed sequence of behavioral 
events. A female pollinator wasp (1.2- 1.8 mm in length) arrives at 
and immediately begins antennating a syconium. The wasp assumes 
a characteristic pose during this “assessment behavior.” The legs are 
extended and the head and sternum are well clear of the syconium 
surface. The antennae are arched up and the distal portion of the 
antennae contact the syconium surface perpendicularly, with only 
