CICINDELIDAE TIGER-BEETLES 



203 



meiits of tlie palpi and lalirum (Fig. 91). The tiger-beetles, 

 like most other Insects that capture living prey, do not consume 

 their victims entire, but subsist chiefly on the juices they 

 squeeze out of them ; the hard and innutritions parts are rejected 

 after the victim has been thoroughly lacerated and squeezed; the 

 mouth forms both trap and 

 press ; the palpi spread out 

 in order to facilitate the 

 rapid engulfing of a victim, 

 then close up under it and 

 help to support it in the 

 mouth ; while the labrum 

 above closes the cavity in 

 the other direction. The 

 mouth itself is a large cavity 

 communicating very freely 

 with the exterior, but so 

 completely shut off from the 

 following parts of the ali- 

 mentary canal that it is 

 difficult to find the orifice of 

 communication ; the labium 

 being much modified to 

 form the posterior wall. 

 For the capture of the prey, 

 always living Ijut of various 

 kinds, a mechanism with great holding power and capable of 

 rapid action is required. The mouih of the terrestrial Manticora 

 (Fig. 91, B), exhibits great strength ; some of the chitinous parts 

 are extremely thick, the mandibles are enormous, the palpi, how- 

 ever, are comparatively low in development. In the arboreal 

 genus Pogonostoma the palpary structures (Fig. 91, A) attain a 

 development scarcely equalled elsewhere in the Insect world. The 

 great majority of the (Jicindelidae are inhabitants of the warmer, 

 or of the tropical regions of the world, and very little is known as 

 to their life-histories ; they show great diversity in their modes 

 of hunting their prey. Some are wingless ; others are active on 

 the wing ; and of both of these divisions there are forms that are 

 found only on trees or bushes. Some, it is believed, frequent 

 only the mounds of Termites. The characteristic feature common 



91. — Mouth - parts of tiger - beetles. 



Profile of Pogonostoma sji. (Madagascar) : a, 

 antenna ; &, labial palp ; c, maxillary palp ; 

 (/. palpiforni lobe of maxilla ; e, mandible ; _/', 

 labrum. B, Section of head of Manticora 

 'inaxiUosa (South Africa) : a, front of upper 

 part of head-capsule ; h, gula ; c, tentorium ; 

 d, eye ; e, labrum ; /, left mandible ; g, max- 

 illa ; h, maxillary palp ; /, labial palp ; k, 

 support of this palp ; /, labium. 



