Cecidomyia destructor in Great Britain. 



3 



destructor, and 2, o 

 G. tritici ; both maf 



mentioning that I have devoted especial attention to 



the study of Cecidomyideous larvae and the form of the 



anchor process for some years ; the 



subject was therefore one with which 



I was conversant. The peculiar 



alteration in colour of the larva in 



this early stage of partial pupation 



was also what is described by Dr. 



Wagner, and accounted for by him 



as the result of the formation of 



adipose matter. In a more advanced 



stage the colouring further changed to that stated to 



accompany the first development of the parts of the 



embryo imago. 



To return now to the larval contents of the puparium. 

 The form of this corresponded with the very exceptional 

 form of that of the C. destructor. It resembled a flax- 

 seed so nearly that on mixing flax-seeds and puparia 

 together it was impossible at a glance to detect the 

 difference. On more minute examination the figures of 

 the puparia were narrower, and, though they had the 

 flattened form of the flax-seed, they were distinguishable 

 by one extremity having a mark across, as if it had been 

 pinched in, the other being slightly bent forward. These 

 appearances are characteristic of the C. destructor pupa- 

 rium at this stage. At first (as it was an early condition 

 of pupation) I did not find the longi- 

 tudinal striae ; the outer skin, which 

 had changed to chestnut-brown of 

 lighter or darker tints, according to 

 its age, still preserved the slight 

 transverse markings, showing the 

 divisions of the segments in the 

 larval state. As the colour deepened 

 the stria? appeared, and were clearlv Pu P aria > na *- s l ze and 



■ ■■,-, x £ , '., ,. ,, j, * 7 magnified. 



visible running longitudinally from 



one extremity to the other, in the manner shown in my 



own figure from life sent, accompanying. 



As I was unwilling to rest on my own opinion in such 



an important matter, I forwarded specimens of the 

 to our Life-President, and trust I shall 

 order in giving his own words. After 



infested stems 

 not be out of 

 thanking me 



for details, &c, 



Hessian Fly," he wrote — " There 



of "Attack of the 

 can be no doubt that 



