100 MB. E. P. STEBBING ON THE LIFE-HISTOKY OF 



{Abies JFebbiana). I further came to the conclusion that the Himalayan species was 

 distinct from the European species Chennes viridis and C. (Metis. 



In two papers read before the Members of the Asiatic Society of Bengal in 1903 *, 

 I save a brief account of the life-history of this Chermes, which I named Chermes ablet is- 

 picece, on the Spruce and Silver Fir so far as it was then known to me. 



I have now abandoned the specific name of abietis-picea in favour of himalayensis, 

 since the former would give rise to considerable confusion should Cholodkovsky's 

 opinion that C. abietis and C. picece are true species stand the test of careful 

 breeding-experiments. 



The first paper treated of the mode of development of the alar appendages of the 

 Spruce form of the insect on its issue from the gall or pseudo-cone, whilst in the second 

 a general account was given of some of the stages of the parallel series passed by the 

 insect on the two trees, so far as was then known to me. 



Whilst on furlough in England in 1904 I paid a visit to St. Petersburg, where I had 

 the pleasure of meeting Professor Cholodkovsky, the well-known eminent authority on 

 the genera Chermes, Lachnus, &c. I was thus afforded an opportunity of a full 

 discussion on this subject with the able Doctor. He fully confirmed my views as to 

 the Chermes of the Himalaya being an undescribed species, and expressed the greatest 

 interest in the marked differences in the life-history as then known. 



Subsequent investigations — as yet, I am fully aware, by far from complete — have 

 enabled me to throw some further light on the existence of this remarkable insect and 

 to correct some of the data given by me in my papers read before the Asiatic Society. 



1 am also able, owing to the talent and assiduity of my wife, to supplement this 

 account with some valuable and interesting coloured plates drawn on the spot from 

 living specimens collected during a recent tour in Chamba State in the Himalaya. 



The general Life-History of the Insect on the Spruce and Silver Fir. 



Chermes himalayensis, as the Indian species is named, closely resembles the European 

 Chermes viridis, K-atz., in that the individuals of one generation may assume different 

 habits at different stages of their existence and so set up the phenomenon known as 

 " parallel series." Also the apterous forms of the insect are parthenogenetic, and, as we 

 shall see, several generations of these parthenogenetic females may be passed through 

 on one host plant. The insect lives on two host plants, the Spruce and Silver Fir, and 

 different stages in the life-history may be passed on either the one or other of the two. 



Blochman and Dreyfus in Germany, Cholodkovsky in Russia, and, more recently,. 

 E. R. Burdon, of Cambridge, in the 'Proceedings of the Cambridge Philosophical Society,' 

 have made a series of most important and interesting observations on the habits of the 

 European Chermes — Cholodkovsky in his erudite " Monographic der Coniferen-Lause " \ 



* Jour. As. Soo. Bengal, vol. lxxii. pt. ii. pp. 57, 229. 



f Cholodkovsky: " Beitriige zu einer Monographic der Couiferen-Lause," Hora; Societalis Entomological 

 Kossica?, t. xxxi., Jul}- 1890. 



