OUR HOUSEHOLD INSECTS 



of the insect. Of the three divisions of the body, the head 

 is the smallest (Fig. 86) ; its hinder part is of an oblong 



FIG. 86. Head of Bed-Bug, with Rostrum extended, a, antennae; c, crown; 

 e, eyes ; I, labrum ; r, rostrum. N.B. The last joint of the antennae and 

 part of the next have been removed. 



shape, broader than long ; the eyes form projecting knobs 

 at the sides, and the base of the mouth organs a con- 

 siderable prominence in front, whereby the head, as a 

 whole, acquires roughly a pentagonal outline. 



The mouth organs form a sort of beak, called the 

 rostrum; and this, as is usually the case in the Hemiptera, 



is tucked back underneath 

 the head (Fig. 87), running 

 along the central line, as 

 far as the base of the first 

 pair of legs, the head being 

 slightly grooved beneath for 

 its accommodation. At its 

 junction with the head, the 

 rostrum is more flexible than elsewhere, so that it can 

 be brought out from the position of rest and held either 



FlG. 87. Side view of Head of Bed- 

 Bug, showing position of rostrum 

 (r) in rest. 



