250 Variation in the Mealworm, Tenebrio molitor 



Eyes 

 Mandibles 



Head 



Antennae 



Mouth parts 



Mesopleura 



Metapleura 



Trochanter "j 



Tibia I of the 6 legs 



Tarsus J 



5th abdominal segment 



Pro thorax 



3rd and 4th abdominal 

 segment' 



Coxae ... 

 Femur ... 



black. 



light to chestnut brown. The epister- 

 num is considerably darker than 

 the epimerum. 



light orange red. 



white with a yellow brown spot on 

 right and left. 



white, with brown spot above the 

 cotyle. 



I white, excepting the fore and hind 

 ( edges, which are light brown. 



Neck 



Elytra 



Prothorax (ventrally) . . . 



Mesostemum 



Metasternum 



1st and 2nd abdominal 



segment 

 Scutellum 



y entirely white. 



From this initial stage till the adult coloration of the beetle some 

 time elapses that may be shortened considerably by a rise in temperature. 

 This influence on the speed of coloration may be gathered from the 

 table on page 251. 



Here we have to revert again to the BA larva, mentioned on p. 228. 

 Beforehand the fact should be borne in mind that no constant difference 

 can be observed between the OR and the CB beetles, either in the 

 course of the development of their coloration or in the individuals that 

 have completed their colouring. In general the black colour of the GB 

 beetles is deeper ifean that of the OR beetles, whose hue is often (by no 

 means always) more a chocolate brown. 



The beetles of the BA larvae are distinguished from the beetles of 



