64 NINETEENTH REPORT STATE ENTOMOLOGIST OF MINNESOTA—IQ22 
Habits of the Adults 
When the adult Perillus comes forth from hibernation in the spring, 
it has first of all a thirst for sap from the potato vine. ‘This is well 
illustrated by describing the actions of two males and six females 
which were observed in one lot confined in breeding cages. These 
bugs were kept fairly inactive until May 20 when they were placed 
in jars with potato beetles and exposed to outdoor temperatures. ‘These 
bugs showed no great desire to attack the potato beetles provided, 
and fed only sparingly when mutilated beetles were offered them. 
On June 2, potato leaves containing eggs of the potato beetles were 
introduced into the cages. Immediately all the bugs became active, 
extending their beaks and probing around on the leaf surface, very 
quickly inserting the rostrum in veinlets of the leaf in preference to 
feeding on eggs of the potato beetle. Two of the bugs actually probed 
at the egg masses of the beetle, then without paying further attention 
to them, turned to feed on the leaf. Following a period of thirty 
minutes all six bugs were still drawing sap from the potato leaves. 
After thirty-five minutes, one of the males began paying attention 
to a female, whereupon copulation soon took place but without the 
female removing her rostrum from the leaf. Shortly after the thirty- 
five minute period of feeding, two female bugs turned to feed on eggs 
of the potato beetle. Following forty-five minutes of sucking sap 
from potato leaves, the last of the six bugs turned to feed on eggs of 
the potato beetle. Having finished their first meal on sap of potato 
leaves, these bugs were never again observed to probe at leaves for 
sap, altho they were watched closely each time fresh leaves were 
placed in the cages. Among hundreds of bugs confined in breeding 
jars during summer months, only two were ever observed in a feed- 
ing position on a leaf, and it seemed doubtful if these bugs were actu- 
ally drawing sap. One of these bugs stood with rostrum extended to 
the leaf for nine minutes, but the movements were not such as usually ° 
occur with feeding, and the conclusion reached was that the bug merely 
chanced to remain resting in that position. Why these bugs should 
desire to draw gap from potato leaves only once, and that the first 
chance they get after emerging from hibernation, is a mystery. One 
can only guess that following hibernation sap is required for some 
physiological function in the process of bringing the body fluids 
back to normal from the condition of great density that obtained in 
hibernation. 
Adults of Perillus feed on eggs, larvae, and mature potato beetles, 
apparently taking the stage that is most convenient. Beetles are 
