COLEOPTERA 



Larvae. — Owing to the difficulty of rearing Coleoptera, less 

 is perhaps known of their life-histories than of those of other 

 Insects. Tliey exhibit, however, extreme diversity correlative 

 with the great specialisation of so many beetles to particular 

 kinds of life. Most beetles must have exactly the right condi- 

 tions to live in. The larvae of many forms are known. Tliey 

 are composed of a head, three thoracic segments (usually very 

 distinct), and a number of abdominal segments varying from eight 

 to ten. Coleopterous larvae are usually described as having nine 

 abdominal segments ; and it is Ijut rarely that ten can be readily 

 detected ; they are, however, visible in various forms, as is the 

 case in the form figured (Fig. 84). A great many of them 

 possess a peculiar pseudopod at the underside of the body near 

 or at the extremity ; it can in many cases be entirely retracted 

 into the body, and is generally described as being the pro- 

 truded termination of the ali- 

 mentary canal. Inspection of a 

 series of larvae shows that it 

 represents a body segment : it is 



Fig. 84.— Larva of a beetle, Family sometimes armed witll liooks. 

 Cerambycidae ('] Aromia moschata). mi ■ o n ji • i 



The first spiracle is placed just at the Three pairs of Small tlioracic legs 

 hind margin of the large prothoracic are often present, but are very 



segment. (From La Massane. ) „ i , i i mi 



oiten completely absent. Ihese 

 thoracic legs may be present in the young larva, but not in the 

 older {Bruchns). The usual number of spiracles is nine pairs, 

 one prothoracic, eight abdominal ; but this is subject to many 

 exceptions, and mesothoracic and metathoracic stigmata are occa- 

 sionally found. The figures we give in the following pages w'ill 

 enable the student to form some idea of the variety of form 

 exhibited by beetle larvae. 



Pupation usually takes place in a cavity in the earth, or 

 near the feeding-place, but a great many species form a cocoon, 

 composed either of fragments of earth or of wood, and slightly 

 cemented together. A few suspend themselves liy the tail after 

 the manner of butterfly caterpillars (Cassididae, Coccinellidae). 

 The pupae are usually extremely soft, their appendages not 

 being fastened to the Ijody. But some pupae (Staphylinides) 

 are truly obtected, having a liard shell and the rudimentary 

 appendages listened by exudation to the body, like Lepi- 

 dopterous pupae, and others (Coccinellidae) are intermediate 



