1985] 
Hager & Kurczewski — Cleptoparasitism 
455 
P. aurifacies 
1.6 
0.81 
□ 1 st generation 
□ 2 nc * generation 
> 
(0 
■8 2.4-1 
-o 
9 
© 
jS 1.61 
o 
lx 
S. vigilans 
0 . 8 - 
10 11 12 13 
HOUR OF DAY 
14 
15 
16 
Figure 2. Hourly activity of Senotainia vigilans and Phrosinella aurifacies during 
first and second generations of Ammophila harti, combined for 1982 and 1983. There 
are no data for P. aurifacies during A. harti’s second generation due to low 
population. 
quency) for the entering behavior may not reflect actual larviposi- 
tion. A nest that contained decaying prey remains and/or puparia 
near the cell was presumed to have been parasitized and those in 
which a maggot or maggots were found were obviously parasitized. 
Four larvipositions by S. vigilans were successful when the attack 
occurred on the initial prey placed in the cell. None of the 16 attacks 
which occurred on a subsequent provisioning of a nest were success- 
ful. If entering behavior is included, the success frequency of clepto- 
parasitism on first provisioning drops to 72.7% (8 of 11) and 
successful attacks on subsequent provisioning increases to 7. 1% (2 of 
28). In total, only 25.6% of the attacks resulted in successful 
