6 ARKIV FÖR ZOOLOGI. BAND 6. N:0 7. 



come conical and nearly as long as they are wide at the 

 base; especially those of the meso- and metathoracic segments 

 project in the 4th larval stage far sidewards, probably on 

 account of the development of the imaginal discs ofthelegs. 

 It is obvious, that, as the larva depends on its mouth- 

 parts for making a way for the body, much is demanded of 

 them alread}^ during the first stage. In accordance with 

 this the head capsule is comparatively larger in this stage 

 than in the following ones, during which it becomes compara- 

 tively smaller. If we compare the greatest width of the 

 head capsule with the length of the body and calculate, how 

 much 7o of the latter it is in the different stages we find 

 that in the 1st stage it is 20,8 Vo, in the 2nd 18,9 ^/o and 

 in the 4th not more than 15,i % of the length of the body. 



3. The pupa. 



The pupa (Figs. 1 & 2, Pl. I) is at first white, but 

 becomes gradually blackish and finally almost dead-black. 

 It is 2,5 mm. long. 



For the general shape and colour I refer to the figures; 

 it is however to be observed that the wings and legs are 

 more closely pressed to the body. 



The head and the prothorax have some very characte- 

 ristic bristles which Letzner already noticed. On the rostrum 

 there are in all 4 pairs, three of which are inserted in a 

 longitudinal row in the basal ^/s and are almost equidistant, 

 while the 4th pair is placed more laterally, at the base, and 

 forms a transverse row with the hindmost one of the longi- 

 tudinal row. At the top of the vertex there is one pair, 

 which points straight forward. On the dorsal side of the 

 prothorax, a little behind the middle, there is a transverse 

 row of black, straight and sharply pointed bristles, which 

 stånd out perpendicularly. On the mesothorax there are two 

 pairs of small inconspicuous bristles, placed close together in 

 an oblique row, and on the metathorax we notice two 

 similar but somewhat larger bristles placed more laterally. 



