252 Bulletin Wisconsin Natural History Society. [Vol. 5, No. 4. 
growing intimacy with the habits of the Crabronidoe and a feel- 
ing of disappointment and chagrin was experienced when it was 
seen that a colony of slender, black wasps had usurped this haunt 
of a more beautiful though coarser structured family. Nothing 
remained of the numbers of Crabro ohscurns, chrysargimis, sex- 
mactilatus and montanus which formerly nested here. During the 
summer but one Crabro brunneipes ventured to dispute the right 
of possession with Psen and built her nest in the log. One speci- 
men of Psen was caught carrying a leaf-hopper to this log last 
year, but others must have builded to account for the numbers 
that chose this for a nesting site during the present season. ' 
The flight of the wasp is rather slow and not graceful. When 
hunting for a place to begin excavations she frequently alights and 
tests rather methodically here and there, walking from place to 
place, occasionally taking wing along the log in arcs with the 
side of the log. She is not at all shy, seemingly indifferent as to 
whether she is ])eing watched or not even though the observer 
be quite close to the nest. The numerous parasitic flies which were 
constantly about the nests also did not seem to be a disturbing 
factor, although several times the returning wasp lunged at one 
which happened to be too close to the entrance. The prey of the 
wasf seems to be exclusively adult leap-hoppers, of which the 
following species were found in the nests : Cyrtolobus fenestra- 
tus Fitch and Atyma inornata Say. 
The method of carrying the hopper was practically the same 
in all instances. It was firmly grasped at the neck or anterior 
part of the thorax by the middle legs, ventral or lateral side 
uppermost, and projected backwards under the abdomen of the 
wasp. Occasionally the body was carried somewhat to the right 
side and below thus pushing the abdomen of the wasp to the left. 
In no instance was the wasp seen to fly directly into the nest, but 
alighted some inches away and deliberately walked in without 
shifting its grasp on its victim. 
