98 
The Bulletin 
» 
at the rate of 500 bill bugs per acre actively at work in the field. 
This number increases to nearly 1,200 per acre by 8 o’clock; this num¬ 
ber remaining practically constant until 10 o’clock, when the number 
actively at work usually falls off rather rapidly to about 500 per acre 
at 12 o’clock. This number remains practically constant until about 
3 o’clock, when the numbers commence to increase gradually up to 
from 900 to • 1,000 by 5 o’clock. This number remains practically 
constant until 7 o’clock, when the number decreases very rapidly,*- so 
that by 9 o’clock practically every bill bug in the field lias ceased his 
activities for the day, and if the weather remains cloudy these activi¬ 
ties are not resumed until the following morning between 3 and 4, 
when a few of the earliest to cease their activities then again become 
active for the new day. 
HABITS OF THE ADULTS 
The egg-laying habits of adults are touched upon in another con¬ 
nection (see methods of oviposition below) and the general daily activi¬ 
ties of adult bill bugs have been discussed under the heading of diurnal 
activities. However, the general feeding, mating, and other habits 
have not been discussed. 
In discussing the habits of bill bugs one is almost forced to use terms 
which have long been used to denote conscious human actions. The 
writer has no intention of implying that either the stimulus or the 
reaction is the same as it would be in human beings, to produce the 
results described. He has merely used these terms because they happen 
to give the clearest picture of the reactions of bill bugs to certain com¬ 
plexes of stimuli. 
The adults feed at or near the level of the ground, tearing away the 
outer leaves of the plant so as to be able to get at the tender growing 
leaves or bud of the plant. In feeding, the bill bug always assumes 
a position with head downward. When the plant is young the bill 
bug may feed at a distance of an inch or two above the surface of tlie 
soil, but usually they have the head and thorax below the surface and 
not infrequently practically the whole body will be below the surface. 
Occasionally the adults are so completely buried that their presence is 
not suspected until the plant is pulled up, when the adult will be found 
clinging to the portion of the stem below ground. Usually, however, a 
portion of the pygidium is left exposed, so that close observation will 
reveal the presence of the adult. This, however, requires very close 
inspection, for, as explained above, the color of the bill bug very closely 
approximates the soil in which it is living, due to the fact that small 
particles of the soil adhere to the body. 
The bill bug is not easy to dislodge from the corn plant while it is 
feeding. When disturbed it clings to the stalk of corn by means of 
the tibial spines, so that usually part of the stalk of corn is torn away 
before the bill bug is removed. 
