52 
Psyche 
[April 
mud between the mandibles and adding further material con- 
centrically within until only a minute opening remains. This 
she plugs with a small bit of mud and then apparently smooths 
out the surface of the whole. In the nest of wasp No. 2 a vacant 
space about 10 mm. long was left between the outermost oc- 
cupied cell and the entrance. 5 The closure was flush with the 
surface of the entrance block; it was a plug of cement twice as 
thick as the partitions within and not smoothed off outwardly. 
The nest of wasp No. 3 was made in a tube which differed 
slightly from that shown in the figure (Fig. 1) in that the outer 
end of the tube was flush with the entrance, there being no en- 
trance block. In this nest the outermost cell reached the entrance 
of the nest, no empty space having been left by the wasp as in 
the former case. The glass tube had an inner diameter of only 5 
mm. The wasp had adapted her construction to this smaller 
diameter by making the cells longer. The comparative lengths 
of the cells in this nest and the number of caterpillars provided in 
each were as follows: cell No. 1,-17 mm., 6 caterpillars; No. 2,-17 
mm., 7 caterpillars; No. 3,-11 mm., 3 caterpillars; No. 4,-5. 5 
mm., 3 caterpillars. The caterpillars appeared to be of two 
species and perhaps represented two families (Pyralidse and Tor- 
tricidse?) . 
The following tabulation gives the life histories of the wasps 
in nests 2 and 3. 
Nest No. 2. 
Date of 
Cell No. 1 
Cell No. 2 
Cell No. 3 
Cell No. 4 
$ 
N 
cf 
cfl 
Oviposition 
June 13 
June 14(?) June 14(?) June 15(?) 
Hatching 
June 16 
June 17 
June 17 
June 18(?) 
Cocoon spinning 
* 
June 23 
June 23 
June 23 
Pupation 
June 30 
June29(?) June 29(?) June 30 
Imagination 
July 13 
July 9(?) July 9 (?) 
July 10(?) 
Emergence 
July 15 
July 11 
July 11 
July 11 
Death 
Oct. 15 
July 19 
Oct. 15** 
Aug. 17 
*This wasp 
curiously 
spun no cocoon, only 
a few loose 
threads. It became inactive June 25. 
**Death of this male may have been hastened by falling 
into the sirup, supplied as food. 
^According to Roubaud (1916) such empty cells are evidently for the purpose of confusing 
parasites. 
