THE COSTCIIUELA. 
35 
temperature conditions, as will be further discussed under the 
subject of hibernation. 
RELATION OF TEMPERATURE TO ACTIVITY OP ADULTS. 
Observations were made in October on some surviving specimens 
of the lots included in Table IX for the purpose of obtaining infor- 
mation on the effect of temperature on the feeding of these insects. 
The number of observations is too small to determine this point in 
more than a general way, and we are justified only in concluding 
that the degree of temperature at which feeding ceases is between 
52° and 60° F. 
Table XII. — Observations on relation of temperature to feeding of the conchuela. 
Date of observation. 
• 
Hour. 
Tom „„ r Number 
atX ofadults 
ature - feeding. 
Number 
<*£j» Remark, 
feeding. 
1905. 
October 11 
8 p. m. 
7.15 p. in. 
8.30 a. m. 
8.15 p. m. 
i. in. 
°F. 
55-60 
49 
52 
51 
8 



Specimens in laboratory. 
12 Do. 
14 Specimens out of doors. 
19 Specimens in laboratory. 
a 19 ! Do. 
October 19 
October 20 
Do 
October 21 
a Including one with seta; inserted in boll, but motionless and evidently not feeding. Plant-bugs in 
the laboratory have even been observed to die in this position. 
For comparison, observations were also made with a miscellaneous 
lot of Pentatomids, including specimens of Pentatoma sayi, EuscMstus 
servus, Nezara hilaris, and Thyanta custator. These are summarized 
as follows: 
Table XIII. — Observations on relation of temperature to feeding of miscellaneous 
Pentatomids. 
Dale of observation. 
Hour Tempera- 
llour - ture. 
Number of 
adults 
feeding. 
Number of 
adults not 
feeding. 
1905. 
October 11 
8 p. in. 
7.!.") p. ni. 
8.15 p. in. 
66 
52 
5 
4 

5 
3 
October 19 
October _'() 
7 
PERIOD OF I\ci BATION 
As is the case with all insect eggs, the developmental or incubation 
period of the eggs of the conchuela is influenced to a marked degree 
by slight variations in temperature. From the entire lot o( egg- 
batches deposited in the laboratory, numbering over 160, 26 have 
been selected for a study of the relation o( temperature to incubation 
period, owing to the comparative completeness o( the records. The 
