October, ’18] 
FLINT: CHINCH-BUG ENEMIES 
417 
These experiments showed that where first and second instar chinch- 
bugs were offered as food, the chrysopa larvae ate from four to six per 
day and that about 100 of these nymphs would be required for the 
chrysopa to complete its growth from egg to adult. Counts made in 
cornfields after the first of August showed that chrysopa larvae would 
average about six per hill of corn in fields where chinch-bugs were 
abundant. 
The damsel bug, Reduviolus ferus. During the past chinch-bug 
infestation this insect has been noted as probably the most common of 
any of the insects feeding upon chinch-bugs in all situations. 
Insectary experiments with this species showed that both nymphs 
and adults fed readily on chinch-bugs, that they seemed to prefer 
chinch-bug nymphs in the third or fourth instar and occasionally fed 
on adults. An average of about two chinch-bugs per day were eaten 
where the observation extended over a period of two to three weeks. 
Blechrus glabratus. This small, very active beetle apparently feeds 
only on chinch-bugs in the first and second instars, its size making it 
very difficult for it to overpower the larger bugs. In the insectary 
experiments one of these beetles ate eighty-eight chinch-bugs in twenty- 
six days. In another case eighteen first instar chinch-bugs were eaten 
in twenty-four hours. 
These beetles can be found in the adult stage in all grain fields after 
the middle of June. They have been taken in fairly large numbers in 
the hibernating quarters of chinch-bug, especially in the bases of the 
large clump farming grasses. 
Another fairly efficient chinch-bug predator, although not occurring 
in grain fields in very large numbers, is the Nabid, Pagasa fusca. All 
stages of this insect from small nymphs to adults have frequently been 
seen in infested fields feeding upon the chinch-bug. In the insectary 
experiments with this insect all specimens used died during the molting 
process although in some cases one or two molts were successfully 
completed. For this reason no complete records of the number of 
chinch-bugs eaten by individuals of this species was obtained. This 
insect seems to prefer the later stages of the chinch-bug and has been 
seen a number of times in the fields feeding upon adults. 
In the insectary experiments this species ate from one to two chinch- 
bugs per day for a period of from five to thirty-six days. 
During the hatching period of the second brood of chinch-bugs one 
of the most efficient of their enemies is the predatory flower bug, 
Triphleps insidiosus. This insect has been seen in small numbers 
in infested fields of small grain but has been found in abundance in 
the cornfields during late July, August and September. The small 
size of this insect makes it impossible for it to feed upon any but first 
