a 
THE GRAIN BUG. 31 
beneath the surface of the ground, as many individuals in this stage 
have been dug from the soil underneath the hibernating quarters early 
in the spring. This fact was not definitely established, however, ow- 
ing to the difficulty encountered throughout the winter in examining 
the frozen soil of these locations. 
Eight specimens of the tachinid Ocypterodes euchenor Walk. were 
reared from several hundred adults of Chlorochroa sayi kept in con- 
finement during 1916. The species has been observed infrequently 
in the field and must be considered of only minor importance in the 
natural control of C. sayi. Its life cycle and habits, as far as ob- 
served, were very similar to those of Gymnosoma fuliginosa. 
PREDACIOUS ENEMIES. 
The offensive odor secreted by the scent glands of Chlorochroa 
sayz has been commonly supposed to protect them from the attacks 
of predatory enemies. While this odor may act as a repellent to 
some of its enemies, in the case of C. sayz the different stages of the 
insect are preyed upon by quite a variety of both vertebrate and in- 
vertebrate enemies. Considered individually these enemies are not 
of great importance in the control of the pest, but in the aggregate 
they undoubtedly exert considerable influence in the reduction of its 
numbers. 
PREDATORY INSECTS. 
The adults of the malachiid beetle Collops bipunctatus Say 
feed upon the eggs of Chlorochroa sayi in the field. This small 
beetle is very numerous in the grain fields of New Mexico and ap- 
parently is one of the most effective predatory enemies of the grain 
bug. In confinement a single adult of this species devoured in one 
day an egg cluster consisting of 10 eggs, consuming even the ege- 
shells. The same individual, however, refused to feed upon small 
nymphs of C. say. | 
When confined in cages the adults of C. sayi frequently fed upon 
their own eggs, but this habit has not been observed in the field. 
The adults of Sinea spinipes H. S. and of Phymata erosa Stal 
have been observed feeding upon the nymphs of the grain bug in the 
field. 
BIRDS. 
The Bureau of Biological Survey reports that Chlorochroa sayi 
has been found in the stomachs of the nighthawk (Chordeiles vir- 
ginianus) and the meadowlark (Sturnella neglecta), and that indi- 
viduals of other species of the same genus have been found in the 
stomachs of the bobwhite (Colinus virginianus), kingbird (Tyran- 
nus tyrannus), Brewer blackbird (Huphagus cyanocephalus), Frank- 
lin gull (Larus franklini), and English sparrow (Passer domesticus). 
