806 



ON THE LIFE HISTORY OF "WIREWORMS" OF 



THE GENUS AGRIOTES, ESCH., WITH SOME NOTES 



ON THAT OF ATHOUS HAEMORRHOIDALIS, F.i 



PART III 



By a. W. RYMER ROBERTS, M.A. 



(Zoological Laboratory, Cambridge.) 



(With 1 Text-figure and Plates XHI, XIV.) 



AGRIOTES SPUTATOR, L. 

 Or the life history of this species as distinct from that of other members 

 of the genus, not much is as yet known. Kollar in 1837 referred to the 

 larva as feeding on lettuces and describes it as being "hght yellow, from 

 six to seven lines long, of the thickness of a pigeon's quill." Curtis(5) 

 (p. 167) and other writers of the nineteenth century seem to have taken 

 their accounts of the species from Kollar, whose details are so very 

 meagre. Adrianov(i), however, as has already been mentioned, obtained 

 the ova and young larvae in Russia in 1914. But he does not appear to 

 have grown the larvae for more than a year and his description of 

 the experiments he made provides no means of distinguishing this larva 

 from others of the same genus. 



My own attempts to breed this species from the egg have, from one 

 cause or another, not been very fortunate, though I have obtained ova 

 from my breeding pots in three separate years. The longest-lived brood 

 did not quite survive two years (1916-1918), but from it a few points 

 have at least emerged; firstly, that the rate of growth of the larva within 

 the time named was almost the same as that of A. obscurus of the same 

 age, and secondly particular features of the structure have been observed, 

 providing the Hnk connecting the young larvae with older larvae which 

 were taken in the field and from which beetles were bred. 



In regard to the first point, only two larvae were obtained after the 

 second winter, but if these can be considered to be of normal size, as is 

 probable, and if their future rate of growth would have corresponded 

 with the past rate, then it appears that there is but little difference in 



^ A grant has been received for publication of this paper. 



