Ifo- 1- ] ^^&'>f Gall-maJcinfi Ajihid. 71 



A NEW GALL-MAKING APHID. 

 By G. B. Buckton, P.R.S. 



(The p;a]ls, from which these insects were obtained, were furnished hy Mr. C. F. 

 Elliot, who found them on what was thought to be a variety of the Pistacia ierebin- 

 thus, tree with aromatic leaves something the shape of those of the lilac. The trees 

 were found in November 1891, growing in a forest in the dry bed of a broad 

 stony ravine about 3.000 feet above sea-level, near Harnai, on the Sind-Pesbin 

 section of the North-Western Railway, Baluchistan. Almost every tree had a 

 dozen or more of these galls towards the extremities of the branches. Tl>e galls 

 were of every shape ; some empty, some opening, and the flies swarming out ; some still 

 with the yonng insects closed up inside. The fiij;ure sliows the wingad insect with 

 diagrams of its antenna and legs. The size of the specimens is indicated by hair lines. 

 The gall which is also shown is half the actual size. — Ed.) 



Late in December 1891, I received from the Indian Museum several 

 pod-like veg-etable excrescences, eoucerning" which I have pleasure in 

 making the following report : 



These galls were of various sizes, some of them measuring as much 

 as 4*5 inches or 11'5 centimetres in length, whilst others did not exceed the 

 size of a small walnut. In width they were about 3"0 centimetres. 

 The larger kinds had somewhat the appearance of contorted figs, more 

 or less compressed and indented ; but probably they were more cylindri- 

 cal in form when fresh and green. Their prevailing colour was 

 ferruginous-yellow or reddish, shading into yellow and greener tints. 

 The surfaces were furrowed longitudinally with shallow streaks, with 

 here and there small tears of resin of a turpentine consistence and odour. 



The gall-like bodies seem to be formed directly from the leaf stalks of 

 the trees, and not from the leaves. Whilst some of these excrescences 

 were pyriform, others had a singular contorted shape and were twisted 

 like a cork-screw. The galls terminate at their summits in a horny 

 point, which in the five specimens examined were imperforate. 



When cut across, they showed hard and woody walls, varying in 

 thickness from that of card-board to the thickness of pasteboard of per- 

 haps 15 millimetres. Each had but a single cavity, without partitions; 

 and in some cases the outer walls were perforated by one or two small 

 round holes about the size of a large shot. 



In the largest specimen, a rent was found from which the winged 

 insect had chiefly escaped. 



The contents of these chambers consisted of a debris of dead insects, 

 winged and apterous, mixed up with a quantity of fibrous substance and 

 excrementatious matter almost insoluble in water. To the naked eve 

 the mass was of a greenish-grey, mixed up with wings and legs form- 

 ing a tangled heap. 



The microscope showed these insects to belong to the Aphindiute, 



