404 Trans. Acad. Sci. of St. Louis 
creature which can use either mud or pith with equal 
ease, according to its availability. Someone might sug- 
gest that a simpler interpretation would be that the 
mother wasp uses pith for partitions, then brings in 
mud and actually lines the cell with it, making a cocoon 
for the larva after it has devoured its provisions, and 
then the mother, having the mud at hand, goes on using 
it in some cases in lieu of pith for partitioning material. 
The only patent point against this simple theory is that 
in the lining of the roof of the cells is a papery or woven 
dise, almost transparent, which could not possibly have 
been woven by the mother. 
On three occasions during the past three years I have 
removed coleopterous larve from the nests of these 
wasps. These were submitted to Dr. Béving, who 
has identified them as the larve of the leaf-miners of 
the genus Chalepus, and thinks ‘‘that they may possibly 
be Chalepus scapularis Oliv.’? Of course, since this 
wasp uses burrows made by other insects, I have no 
absolute proof that the Odynerus mother stored these 
beetle larve, but since she handles other problems of 
nest-building in an unusual way, I should not be sur- 
prised if she did the unusual thing in provisioning. 
The normal dates of the emergence of this species as 
I have observed them are May 18 to June 15, with the 
largest numbers on June 8 and 9. 
The parasites which emerged from the nests were 
Toxophora amphites Walk. [C. T. Greene], Foenus tar- 
sitorius Say [R. A. Cushman], Epistenia osmiae Ashm. 
[S. A. Rohwer], and Chrysis (Olochrysis) sp. [S. A 
Rohwer]. 
Stenodynerus vagus Sauss. [S. A. Rohwer]. 
An elder twig taken in Shaw’s Garden on July 4, 1918, 
had partitions of mud and two cells; the upper one was 
