Campodeiform Larvae 



105 



ages corresponding with those of the perfect insect, 

 but in a much more primitive condition. Each feeler 

 has but four segments, the third carries, alongside 

 the fourth, a small papilla which shows traces of 

 segmentation, and suggests that the feeler was 

 primitively branched (fig. 64,7). The mandibles are 

 powerful, but each carries only a single stout tooth 

 in place of the complex serrate cutting-edge presented 

 by the mandible of the adult. Each maxilla of the 

 first pair consists of a long basal segment (stipes), 

 on which are placed the blade (laciniaj 

 represented only by a tiny tubercle 

 with a bristle, the hood (galea) con- 

 sisting of two short cylindrical seg- 

 ments and the palp with three segments 

 springing from a short palpiger (fig. 

 64,8). As in the adult, the second 

 pair of maxilla are joined to form a 

 lower lip, but each palp has only two 

 segments. A striking difference be- 

 tween the head of this larvse and that 

 of the beetle into which it will grow 

 is presented by the eyes. No com- 

 pound eyes are present in the grub ; 

 only a group of six simple eyes (ocelli) 

 can be distinguished behind the base 

 of each feeler (fig. 64,6). The legs 

 of the grub are much shorter than those of the perfect 

 insect ; the haunch, trochanter, thigh and shin can be 

 easily recognised, but the foot consists of only one 

 segment (fig. 64,"). At the tail-end of the hind- 

 body is a pair of long cercopods covered with many 

 nodules and stiff bristles (fig. 64,10^. 



Such a six-legged, active grub is known as a 

 campodeiform larva, on account of its general like- 

 ness to the bristle-tail Campodea, a small wingless 



Fig. 65.— Campodea. 

 Magnified 4 times. 



