1968] 
Sheldon — Pison koreense 
1 1 1 
5:00:10 PM with the first load of mud. On this trip she brought 
enough mud to nearly close the cell opening. A second load com- 
pletely sealed the cell. Just before taking flight she paused briefly 
near the cell and appeared to look around. She returned to the 
closed cell twice within the next ten minutes but at neither time was 
any additional mud added to the cell. 
Parasites — • A large number of adult Melittobia chalybii Ashmead 
(Eulophidae) were reared from a P. koreense cocoon collected at 
Kickapoo State Park, Illinois. The cocoon was from a nest con- 
structed in an unsealed cell of Trypoxylon politum. 
The Immature Stages of Pison koreense 
Methods — Preparation of the larvae for microscopic study in- 
volved making two 1 small punctures in the cuticle and then placing 
them directly into Nesbitt’s fluid (Nesbitt, 1945) for 24-48 hours 
for clearing, the length of time depending on the temperature. At 
6o°C less than 24 hours may be required. They were then flushed 
out, by injecting 70% ETOH into the body cavity through one of 
the punctures, and stained in a 5% solution of Chlorazol Black E 
in 75% ETOH for one minute. They were then placed in glycerine 
for storage and study. 
Descriptions were made from cleared, whole specimens, from 
cleared heads that had been removed and mounted in a depression 
slide in glycerine, and from mouthparts that had been removed and 
mounted individually on slides. The spiracle was also mounted in 
glycerine on a slide. Studies of all but the grossest details employed 
phase and Nomarski interference contrast microscopy. Measurements 
were taken with an ocular micrometer and the drawings were made 
with the aid of a microprojector. Following the procedure of Evans 
(1956), the description is based on a single specimen. Individual 
variation is discussed immediately following the description. 
Egg — Length approximately 1.3 mm; width 0.5 mm; subcylindri- 
cal, with a slight taper at one end and slightly incurved on the side 
attached to the spider’s opisthosoma; color an opaque white (fig. 4). 
Larva- body (fig. 5) : Based on a diapausing specimen. Length 
6.3 mm; maximum width 2.0 mm. Posterior end truncate, anus 
ventral and slightly sub-apical on the last abdominal segment. Pleural 
lobes well developed, the thoracic lobes quite protuberant. Posterior 
annulets on the thorax only slightly swollen, noticeably swollen on 
abdomen. A few weak setae present on the dorsum and thoracic 
pleural lobes, very scarce on the venter and restricted to the posterior 
segments. Spiracles (fig. 6) with ridges on atrial wall corresponding 
