1917.] Some South Indian Cecidomyiuls. 306 



empty pupal skin of a fly was borne at the tip, from which 

 circumstance their true nature was easily recognized. These 

 are in all probability the very galls described by Mr. L. A. Boodle 

 in Kew Bulletin No. 3 of 1910 in an article on "Gall- on an 

 Indian Grass." The galls described therein were reported to 

 have been collected by Mr. Talbot, a Forest Officer at Poona. 

 From the material then available, viz. the pupal skins and 

 specimens of young larvae, Professor Kieffer described the fly ' 

 as Oligotrophies ischcemi n. sp I am not aware if the adult 

 flies have been reared and described. In September, 1916, while 

 examining the galls, I had the rare luck of securing two freshly 

 emerged female specimens and one of the male. Two more 

 were also reared out from galls. The females are rather large, 

 black flies with an immense abdomen and short piceous wings. 

 The males are also black but much smaller. The females were, 

 on account of their wings being short, unable to fly. Eggs 

 were readily laid in tubes and hatched in three days. This fly 

 seems to breed only in the rains, and how it passes the long dry 

 season hi these arid plains is a mystery. Possibly the young 

 larvae remain quiescent in the nascent buds underground and 

 develop when the latter shoot out after the rains. 



The above grasses are the only ones in which I have noted 

 these gall formations, but I am sure the number will be doubled 

 or even trebled if the subject be systematically taken up and 

 worked out. 



There are some general factors governing these gall flies even 

 in the matter of parasitisation. The parasites attacking the 

 gall maggots may be divided into two distinct classes: (1) A 

 group, the members of which parasitise the grown-up maggot 

 or the pupa. The mother parasite seeks the gall and inserts 

 its eggs inside with its ovipositor, the grubs that hatch out 

 attack and feed on the maggot or the pupa which is usual!;. 

 Previouslv paralysed bv the mother wasp. Coming under this 

 group are several parasites belonging to two or three families ot 

 the super-familv Chalcidoidea . (2) A second group which para- 

 dises the eggs. The parasites coming under this group are 

 JWtotrupid.. The adult wasp hunts out the eggs of the Ujci- 

 domviid and deposits one or more eggs into each egg. Ine egg 

 thus parasitised hatches normally into a maggot which searcnes 

 f °r and enters the terminal buds of shoots and therein teens 

 and grows. 



In the case of one of the parasites, **&"*£l 

 several eggs seem to be deposited in a. single ^omjud 

 egg, and when the gall maggot becomes lull-grown th .para 

 **» ^rvae (20 to 30 in number) also grow up feeding c* the 

 nternal tissues of the host. Ultimately the «&££*%£ 

 t0 an empty bag, inside which the parasite larvae spin tin, o^al 



1 Prof. Felt has identified it a, Hormomyia iochaemi, kief. 



