302 Journal of the Asiatic Society of Bengal. [N.S., XITT, 



typical hollow shoot emerges in two or three weeks. Though 

 hatching at one time out of the same batch of eggs, the maggots 

 that enter the apical buds complete their development more 

 quickly (at least a week earlier) than those affecting the axil- 

 Ian ones ; and invariably the apical galls are much larger 

 in size than the axillary ones. The full-grown maggot is of 

 pale brown colour and possesses a well-marked breast-plate, 

 the anterior ends of which are prolonged into two pointed 

 horns. The freshly formed pupa is milk-white, but later turns 

 bright -pink The adult emerges in six days. The female is pale 

 brown and possesses a huge reddish abdomen bulged with eggs, 

 while the male is somewhat darker and more slender in form. 

 Most of the eggs are laid during the first night. The male 

 flies seem to go for a drink, soon after emergence, while the 

 females do not display any such thirst. 



2. Panieum puncunum. — A grass very nearly allied to P. 

 fluitans but more thoroughly aquatic. It was collected by me 

 at Samalkota, Godavari District, and showed profuse gall forma- 

 tions. The fly reared out was identical with Dyodiplosis fluvi- 

 al is, reared from P. fluitans. The flies reared from galls of P. 

 punctatum freely laid eggs on P. fluitans at Coimbatore. The 

 maggots that hatched out induced typical gal] -formations in P. 

 fluitans and flies emerged normally from them. 



3. Cynodon dactylon. — As already noted, a collective gall 

 is formed in this grass, from which 2 to 12 hollow shoots may 

 emerge. Such galls were noted on this grass at Coimbatore, Palur 

 (S. Arcot District), Samalkota (Godavari District), and Anaka- 

 palle (Vizagapatam District). The fly which has been identified 

 as Orseolia Cynodontis, Kief and Mass, is smaller, comparatively 

 more thick-set and darker than Dyodiplosis fluvialis. The life- 

 history of this fly has also been studied bv me. The eggs are 

 elongate, reddish and about one-third of a millimetre long and 

 are laid in batches of 3 to 20 along the under (and rarely also 

 on the upper) surface of the top lives of a shoot. The 

 maggots hatch out in three days and creeping between the 

 leaf-sheaths, reach the rudiments of the apical and axillary 

 buds of the shoot. Owing to the irritation caused by the 

 maggots, several of the side-buds of the shoot begin to develop 

 their galls simultaneously, so that the tip of the shoot bulges 



out gradually and a umes the pine-apple form. When mature 

 the hollow shoots appear at the tip and the flies emerge later 

 on. The time taken by the fly to develop into the adult from 

 the egg is about three to six week n. 



4 Ischaemum ciliare.— This is also a common grass at 

 Coimbatore m the wet lands. The galls found on this grass 

 are smaller- and shorter than those on P. fluitans and are de- 

 veloped usually from the axillarx buds towards the base of the 

 plant. *Iies have been reared" and are quite distinct; the 

 wmgs being more distinctly smoky and the body much darker 



