CHBRMBS H1MALAYENSIS ON THE SPRUCE AND SILVER FIR. 105 



also broad, the metathorax sessile on the abdomen. The wings project beyond the 

 posterior part of the body almost 1| times the total length of the Aphid. Length with 

 wings 225 to 268 millim. PI. 21. fig. 5 shows the fly newly issued from its last larval 

 skin with wings still rolled up ; fig. 6 the perfect fly with wings fully developed ; and 

 fig. 7 the fly developing the white cottony material on head, thorax, and body. 



Life-History . 



An examination of the branches of the Spruce at the beginning of May will show 

 small pinkish-white cone-shaped masses appearing here and there. At the bases of 

 these, in the axil between the branch and cone (which is really an unopened bud), masses 

 of elliptical reddish-yellow eggs are to be found, sometimes very abundantly, at others 

 in much scarcer numbers. These egg-masses are partially covered, by the dried skin of 

 what was the stem-mother, who dies after laying them. At the beginning of May these 

 egg-masses are in the majority, few of them having hatched out, and the bud above 

 them having only just commenced to increase in size. I have not as yet definitely 

 ascertained whether these eggs are laid in the spring or in the late autumn by the stem- 

 mother. A careful search for eggs in October and November, 1906, in Jaunsar failed to 

 disclose any on the Spruce, even on trees bearing numerous old galls from which winged 

 insects had emerged the previous July. This would seem to point to the fact that the 

 stem-females (Fundatrices) on the Spruce hibernate through the winter with their 

 long proboscides fixed in the bast-layer of the stem just below a bud and lay the eggs 

 very eaidy in the spring in April — in fact, before the first warmth of spring has made 

 itself really felt and whilst snow is still lying on the ground. This is what I think 

 myself actually takes place. 



According to Burdon, it is the lengthy feeding of the mother by suction which 

 originates the gall-growth on the stem, the growth gradually spreading to and 

 enveloping portions of the needles in the European form. 



In the first week in May small larvae hatch out from the eggs, and sections cut across 

 any of the small cones, which have swollen to a slight extent, will disclose numerous 

 young larvae between the bases of the young needles. These larvae are engaged in 

 feeding upon the sap of a part of the stem and the young undeveloped needles of which 

 the pink cone or gall cousists. The irritation set up by the stem-mother feeding at the 

 base of the bud and perhaps by the young larvae feeding at the base of the young 

 needles soon causes the bud to swell, but instead of opening out into a short stiff brush 

 of needles it develops into a green cone-shaped mass or gall. When this gall is quite 

 young there is no partitioning off into distinct cells to be observed within it ; but as the 

 swelling under the constant irritation set up by the larvae and due to the growth of the 

 needles themselves continues, the interior gradually becomes divided off into distinct 

 compartments, in each of which numbers of the young larvae are to be found engaged 

 in sucking the sap from the walls of the compartment. PI. 20. fig. 2 shows a section 

 across a partially-grown gall with five compartments in it. 



In the third week of May this partitioning is already distinct, and a section of a small 



