1968] 
Sheldon — Pison koreense 
115 
labrum, and the presence of two rows of setae on the clypeus rather 
than one row of setae and one row of setaless sensillae. Obviously 
a great deal remains to be learned about the species characters and 
the individual variability of Pison larvae. 
In addition to the morphological differences between the larvae, 
there are some interesting differences in adult behavior. Micheli 
(1933) gave a fairly detailed description of the nest construction of 
P. atrum in a section of bamboo stem 10 mm long and with a bore 
of 7 mm which he had sealed at one end and placed on the wall of 
a house. The nest constructed by P. atrum within the cavity of 
the bamboo (see his fig. 11) was linear, with the cells end to end 
and separated by mud partitions. The side of each partition facing 
the nest opening was stated to be convex and rough while the inner 
surface was described as concave and smooth. This seems rather 
curious as the construction of a partition with these features would 
appear to be very difficult and is exactly the opposite to that found 
by Cooper (1957) in Ancistrocerus antilope (Panzer) which nests 
in much the same way as P. atrum. Ferton ( 1910) reported a similar 
linear, cavity nest in P. ater sp. which he found nesting in the hollow 
stems of Rubus , each cell being separated by a mud partition. He 
did not, however^ discuss the shape of the partition. Perris (1877) 
reported the rearing of P. ater from a Sceliphron nest. Iwata (1964) 
found P. argentatum nesting on concrete walls and sometimes on 
wooden walls and doors of buildings in Thailand. He also found 
P. obliteratum Smith constructing nests on the rough wall of a room, 
P. suspiciosum Smith nesting in bamboo tubes, and Pison sp. (near 
suspiciosum ) reconstructing the nest of Sceliphron madraspatanum 
for their own use. P. koreense , in comparison, nests in well pro- 
tected localities (see above), but has not been seen nesting in stem 
cavities. 
The few observations that have been made on the prey of Pison 
indicate that spiders of several families are used, although it is pos- 
sible that a given species of wasp tends to be quite narrow in its 
choice of prey. As noted above, I found P. koreense provisioning 
with a number of species of Dictyna (Dictynidae) . Cowley (1962) 
in a study of the New Zealand species P. spinolae found that the 
number of spiders per cell in 14 cells varied from 4-15, with a mean 
of eight. Six genera were represented — all in the family Argiopidae: 
Argiope protense , Arachnura f ere day i, Araneus viriditas, Araneus 
crassus , Araneus laevigatus , Cyclosa trilobata , Cyclosa sp. (unde- 
scribed), and Leucage dromedaria. Ferton (1908) observed P. ater 
in the act of catching a small spider of the genus Xysticus (Thom- 
