346 
T.F. Houston 
fallen 
6 ? 
shaft 
Figure 4 Details of a nest of Rolandia maculata: A, 
profile of partially completed nest; B, plan 
view of cells (1-3) showing relationship to 
shaft. Scale line 5 cm. 
Cocoons 
The occupied cocoons (Figure 5A) were spindle- 
shaped, light brown, 17-19 mm long, 5.5-6.0 mm 
in diameter and had sand grains adhering to their 
coarsely fibrous outer surfaces. Internally, they 
were lined by a sparsely woven and very delicate 
layer of fine silk and between the outer and inner 
layers was a densely woven, felty layer of silk. Both 
outer and inner surfaces were quite dull. The cell 
mouth end of each cocoon had a vestibule 
separated from the main lumen by a partition, flat 
on the outer surface and concave on the inner. 
Faecal material formed a thin meconium covering 
the inner end of each cocoon. 
Two larvae in cocoons were kept in an 
airconditioned laboratory and there was no 
indication of development when the larvae were 
inspected 12-14 months later. That the larvae were 
still alive was evident from writhing movements in 
response to touching. 
Provisions 
The provisions consisted of firm masses of moist 
orange pollen. Pollen samples taken from three 
provisions proved under microscopic examination 
to be homogeneous and consistent with being 
derived from Jacksonia species (Fabaceae), the 
observed forage plants. Completed provisions 
were rather "larviform" in appearance, being 
elongate, segmented and having 5-7 pairs of 
protuberances somewhat like caterpillar 
pseudopods on the underside. Masses were 
thickest towards the cell mouth and tapered 
towards the cell base. Evidently, the provision 
masses are formed of successive deposits of pollen, 
commencing in the inner ends of cells and 
progressing towards the cell mouth. 
Female behaviour 
Nest burrow construction 
Females in the process of excavating burrows 
made frequent short flights from the entrance. For 
example, one female made nine flights during eight 
minutes of observation. Females always reversed 
out of their burrow entrances and hesitated for 
several seconds prior to taking flight. Typically, the 
flights were 3-5 seconds in duration, directly away 
from the burrow in a fixed direction to a set point 
10-50 cm from the entrance and straight back 
again. However, one female repeatedly flew 4 m 
from her burrow. Females slowed as they 
approached their entrances but scuttled straight in 
after alighting. The purpose of these flights was 
not immediately apparent but proved to be for the 
purpose of disposing of excavated sand: a piece of 
blank card placed on the ground beneath the 
turnabout point of two females' flight paths 
revealed that the wasps dropped loose grains of 
sand there with every flight. Because the sand 
grains were scattered loosely, they spread 
imperceptibly over the surface and no tumulus 
was formed. Females carry the sand in a 
psammophore formed between the head. 
