STUDIES ON PERILLUS BIOCULATUS FAB. 65 
frequently attacked even when the more easily managed lavae are — 
abundant. When advancing to the attack, Perillus approaches with 
rostrum extended to the front, ready to insert the mandibles and 
maxillae the moment a soft part of its prey is touched. To make 
the insertion it seems necessary for the bug.to place its front feet on 
the victim, thus gaining leverage to make the puncture, following which 
the bug retires as far as the rostrum will permit. Once the insertion 
is made the prey is securely held by barbs at the tips of the mandibles. 
When attacking beetles the bug usually approaches from the rear, 
inserting its rostrum near the tip of the abdomen or between sclerites 
at the side of the venter. However, Perillus has occasionally been 
observed standing on top of a beetle with tip of rostrum inserted at 
a point where the head fits into the thorax. Having attained this position 
it is difficult for the beetle to dislodge the predator. 
In the potato field, the encounters between potato beetle and predator 
are not without interest. If the potato beetle feigns death when at- 
tacked, and tries to drop to the ground, the victim merely becomes 
suspended from the tip of the bug’s rostrum. However, the beetle 
usually tries to pull away by scrambling rapidly over the leaves of 
the potato plant, dragging along the predator, who clings and pulls 
back at every opportunity. When these tactics fail the potato beetle 
may at times turn upon the enemy with mandibles snapping, trying 
desperately to snip antennae or legs, when they can be reached; but 
Perillus is very agile and usually manages to keep at rostrum’s length, 
except at times when caged in small glass jars for breeding purposes. 
In these encounters, all efforts of Perillus, following the insertion 
of mandibles in the soft integument of the beetle, are directed toward 
dislodging the feet of its prey and trying to keep the victim suspended 
in mid air, where scrambling feet avail nothing. These encounters in 
the potato field invariably result with Perillus the victor, while the 
beetle or grub, following loss of blood, remains suspended over the 
edge of a leaf and the predator finishes the meal undisturbed (Plate 
En hie. 4.) 
In restricted quarters, such as glass breeding jars, Perillus is at a 
disadvantage and is not always able to keep the beetle at a safe distance. 
Therefore when confining Perillus for breeding purposes, and using’ 
adult beetles for food, it was found best to snip the mandibles of the 
beetle to prevent accidents to the bug, such as the loss of antenna or 
leg, which eventually would result in premature death of the bug. 
Mating habits. Following hibernation, and after both sexes have 
had their first spring meal on sap of the potato vine, the bugs begin 
