BULLETIN" 1016, U. S. DEPARTMENT OF AGRICULTURE. 
and during this time are easily captured. During copulation 
the female alone remains active, traveling about frequently, and 
dragging the male- helplessly after her. There is little doubt that 
there are both polyandry and polygamy among the adults of the 
chinch bug, since they mate an indefinite number of times. 
LIFE HISTORY OF THE CHINCH BUG. 
OVIPOSITION. 
Under field conditions eggs are placed by the female near or on 
the plants upon which the insect feeds. Eggs may be found in the 
soil' near the roots, at the base of the plants, but more often occur in 
the leaf sheath, which appears to be the preferred place. 
In the laboratory bacteriological test tubes, of standard size, stop- 
pered with absorbent cotton and supplied with parts of corn plants., 
were found to be the most successful type of egg cage. The corn 
plants used as hosts were about 6 inches high, with their foliage and 
the outer roots cut off before introduction into the cage. Sometimes 
parts of larger cornstalks were used when young corn was not avail- 
able. In cages where young corn was supplied the eggs were laid 
on all parts of the plant, but most frequently were placed under the 
upper epidermal layer of the leaf sheath. This appears to be their 
favorite location, although many eggs were placed in the cotton 
stopper of the vial. Where parts of cornstalks were used, the eggs 
were often found pushed into the pith, on either end, to their entire 
depth, sometimes two and three together. In the leaf sheaths they 
are often found in quantities, side by side. In one instance 16 eggs 
were found placed in this manner in a neat, compact row. With a 
little care the whole rOw was lifted out without any of the eggs be- 
coming detached. It was not often that eggs were placed loosely 
in the vials. It seems that the female desires to conceal her eggs from 
possible predacious enemies. 
Eggs in cages were deposited during all hours of the day. It is 
possible that some may be deposited during the night, but this is 
doubtful. In the field it is quite likely that very few eggs are de- 
posited during early morning hours, the temperature at that time of 
the day being lower and damp, which causes the adults to become 
numb and therefore sluggish. 
NUMBER OF EGGS DEPOSITED BY A SINGLE INDIVIDUAL. 
Considerable variation has been noted in the number of eggs de- 
posited by an individual female of this species. Such variation un- 
doubtedly is governed to some extent by seasonal weather conditions. 
There is no doubt, however, that some females are by nature more 
fecund than others. 
