24 
Psyche 
[Vol. 87 
prey to be dragged, attached by the sting, enabling more efficient 
ground transport (the sting is impaled through a forecoxial corium, 
Steiner, 1979). Other factors may elicit impalement carriage. After 
copulation many females impaled (whether the prey was held pedally 
or impaled before copulation) and then entered their nests. Impaling 
under these conditions may speed up prey transport, minimizing 
further interruptions by males. 
Mortality. Cleptoparasitic miltogrammine flies (Sarcophagidae) 
were regularly present at all sites, with the genera Senotainia and 
Metopia predominant. Miltogrammine maggots were found in 
14.5% (n=75) of the cells excavated at the beach sites, but the Boiler 
site had only 3.7% (n=107). Senotainia flies were attracted to males, 
females and mating pairs. Flies often hovered or perched behind 
copulating pairs though larviposition was not observed. Most flies 
followed the male after separation, enabling the female to provision 
safely. 
One beach site had 13.5% cell mortality due to the ant Solenopsis 
pergandi Forel (Formicidae). This ant appeared to rob cells while 
Figure 1. A female O. sericeus with a fly (Chaetopsis aenea) impaled on her sting. 
Nest entrance is at left. 
