8 ARKIV FÖR ZOOLOGI. BAND 5. N:0 12. 



Second larval stage. 



When it first makes its appearance, the larva is quite 

 white.. but låter it grows somewhat darker. It is at first 

 1,4 4 mm. long and 0,4 mm. wide, but, when fullgrown, 

 attains a length of 1,6 6 5 mm. 



In the shape of the head and the mouthparts the 2^^ 

 stage does not differ from the 1** stage, but the number and 

 size of the dorsal and lateral hairs is different. 



On the prothorax there are two pairs of dorsal hairs, 

 the anterior pair of which, although present even in the 1^* 

 stage, but then very inconsspicuous, has grown and become 

 nearly as long as the posterior pair. The small lateral hairs 

 which were to be found round the base of the pair of large 

 hairs in the P* stage have also grown, almost attained the 

 length of the latter and become glandular. 



On the meso- and metathorax the dorsal pair is greatly 

 reduced in length and is no more longer than the dorsal hairs 

 of the abdominal segments. The space whereon they are in- 

 serted has risen to a short, conical and darkcoloured processe. 

 Of the lateral hairs three pairs have grown so as nearly to 

 match the one long pair of the P* stage. 



On the abdominal segments, the median dorsal hairs have 

 not increazed in size and are consequentty comparatively 

 smaller than in the P* stage; the conical tubercles on which 

 they are inser ted have on the other hand increazed and 

 become more dark coloured. The anteriorly pointing hairs 

 of the two dorso-lateral ones have increazed and attain -^ 

 of the length of the other pair and the portion of the cuticle 

 on which they are inserted has rizen to broad conical processes. 



Finally, on the lateral pleural processes we notice one 

 pair of small slender and glandular hairs which are inserted 

 subterminally, close at the back of the terminal hairs. 



The tips of these hairs are shaped differently from those 

 of the other hairs; they are cut off obliquely so that the 

 ventrai edge is longer, and the dorsal wall is thin and covers 

 the ventrai one in the shape of a thin plate, tripartite at 

 the top (Fig. 7 a, b & c, Pl. L). 



The 3^^ stage attains a length of 2,3 mm. and diffors 

 from the 2°^ one only through the appearance of one pair 

 of hairs at the postero-lateral angles of the prothorax, the 

 growth of the 5^^ dorsolateral glandular hairs of the meso- and 



