422 
Psyche 
[December 
night within their nests, the entrances closed from within. However, 
during the day our impresson was that about half of the nests in 
the colony were left open at any given time. 
No final closing behavior was observed. However, while the 
lateral tunnels leading to the individual cells are always refilled 
following provisioning, the main vertical nest shaft is apparently 
never filled in, and the mound remains to be eventually eroded by 
the elements. Possibly the female constructs a simple plug in the 
entrance of completed nests, as we occasionally observed the en- 
trances of formerly active nests to be plugged with debris, mostly 
short pieces of grass stems and other dried plant parts. Whether 
these apparent final closures were the work of the wasps or the 
elements is unknown. However, related miscophine wasps in the 
genus Solierella often close the burrow with assorted debris, including 
seeds, small twigs, leaves, and sand grains (Kurczewski, 1967). We 
occasionally noted unidentified spiders occupying former nests, and 
Rayment (1955a, b) reports that certain pompilid wasps sometimes 
utilized the abandoned Sericophorus burrows. 
A brief description of two nests of S. viridis roddi Rayment (a 
subspecies of doubtful validity) from Cheltenham, N.S.W., is re- 
ported by Rayment (1955b) ; these nests appear similar in form to 
those of the Black Mountain colony. Also, Rayment reported that 
males were observed flying over a different S. viridis roddi colony 
at Tallong, N.S.W., in the early summer and were often seen to 
enter closed nests. On the basis of these observations, he suggests 
that mating may take place below ground. As we did not discover 
the Black Mountain colony until the nesting season was well under 
way, and never noted evidence of males, we are unable to add any 
information on this aspect of their biology. 
Egg and Larval Development. — Prey are placed in the cell 
head in first, usually venter up, and are strung out more or less in 
a row. The flies are dead or profoundly paralyzed, and remain 
relaxed but wholly immobile for several days. In 17 cells contain- 
ing eggs, the number of flies per cell averaged 5.6 (range 3-9). 
The egg is laid on the first fly placed in the cell (occasionally 
apparently on the second fly), i.e., the fly at the end of the cell 
farthest from the main nest shaft. Cells are mass provisioned, but 
apparently the egg is not laid until after the full complement of 
flies has been placed in the cell, as on several occasions excavated 
nests were found having cells with one or more flies present but 
containing no egg. As in the species studied by Rayment (1955a, b), 
