58 IOWA STUDIES IN NATURAL HISTORY 
most likely to be met with. During this month it also breeds, 
for pairs have been taken in copula on July 22 and 29. On the 
latter date I took, in the vicinity of Riggsville, a specimen which 
had just molted for the last time, the body integument being 
yet soft and delicate. 
On July 18, 1919, a specimen was swept from cinquefoil 
(Potentilla monspeliensis) growing in a low damp place in a 
rye field; again on July 8, 1920, several adults were taken in 
the same place on plants of this species. I have an adult which 
was taken on July 4 in beach drift near the Biological Station. 
Apparently this pentatomid is most at home in low lying 
grass lands or semi-cultivated areas such as are found along 
Bessey Creek or north of North Fishtail Bay as well as, some- 
times, along the shaded areas bordering woodland or in wood- 
land. 
C. bimaculata may be distinguished from any other penta- 
tomid of the region by its size (5.0-7.0 mm.), and its general 
black coloration marked with reddish yellow. 
Banasa dimidiata (Say) 
One of the joys associated with collecting in the Douglas Lake 
region is the likelihood of meeting with considerable numbers 
of this beautifully colored pentatomid, especially during the 
latter part of July and also in August. It is during the first 
few days of August that the height of abundance of adults 
seems to be attained. 
The favorite host plant here appears to be arbor vite (Thuja 
occidentalis), which is a common tree along some portions of 
the lake shore as well as in other places. On August 8, 1919, 
many adults and nymphs, the latter mostly in the third and 
fourth instars, were swept from the small Thujas growing along 
the lake shore north of the Station. At this time, also, egg 
masses were found on the under side of the leaves of the Thuja. 
These egg masses usually contain from ten to twenty eggs placed 
side by side in the ordinary manner of pentatomid eggs. 
The color of both nymphs and adults blends in very well with 
the color of the tree and the lighter green color of the cones, 
which latter, by the middle of August, are about one-half inch 
in diameter. Contrary to my observations on most pentatomids 
