S. A. Arendsen Hein 229 



sometimes finds the statement that both species of larva {T. obscurus 

 and T. molitor) are often found together in the same culture (Everts, 

 p. 265 ; Przibram). 



When the beetles of our two types were bred it soon appeared that 

 my presumption was wrong ; the beetles of the OR and CB larvae are 

 T. molitor beetles, which in spite of a very extensive comparative re- 

 search do not differ phenotypically, or if they do differ it is only in the 

 black colour of the adult GB beetle which, as a rule, is more intense 

 (although not always). So it is highly probable that the above state- 

 ments in the literature are wrong in so far as the GB larvae have been 

 taken for the larvae of T. obscurus, without any further research; in 

 other words, it was not suspected that the larvae of T. molitor may present 

 themselves in two colour-types, the OR and the GB type which are no 

 longer to be distinguished with certainty in the adult beetles. 



2. Larval Anomalies. 



In almost any somewhat extensive culture the following three 

 anomalies may be observed. 



a. Larvae with one or two pairs of rudimentary wings. 



b. Larvae of which two or more segments are partially fused. 



c. Larvae with an increased or decreased number of spines at the 

 distal extremity of the last segment. 



a. Rudimentary Wings. 



On the 3rd and 4th segments' the rudimentary wings appear as flat 

 horizontal outgrowths about half the length of the segment (see Fig. 1). 



Fig. 1. 



This anomaly was only met with in larvae of an abnormally long 

 larval stage. 



1 For the sake of simplicity the head is called the 1st segment, which expression, 

 speaking morphologically, is not correct, though it simplifies the description and orien- 

 tation. 



16—2 



