158 SOME SOUTH INDIAN INSECTS, ETC. [CHAP. XVII. 



in the fruit. Certain strong-smelling oils, such as Citronella and 

 Kerosim. arc known to exercise a powerful attraction for the 

 males of certain species of fruit-flies and exposure of pans of 

 water or fly-papers baited with these oils will destroy the males in 

 large numbers ; but in practice it is not found that the quantities so 

 destroyed have much influence on the oviposition by the females. 



Young cholam plants are sometimes attacked by a fly-maggot 

 which bores in the stem just about ground-level and which may do 

 considerable damage. It is believed that this pest, whose exact 

 identity is not known, attacks healthy plants, but it may possibly 

 pro\ e to beonly a follower of an attack by stemborcr (Chilo simplex). 

 No remedy can be recommended except increase of seed-rate and 

 subsequent thinning out and burning of all young plants seen to 

 be attacked, the attack being marked by a characteristic yellowness 

 and drooping of the young plant. Sometimes more than one 

 maggot may be found in the same stem; the brownish pupa is 

 found in the larval burrow. 



The Red-gram Agromyza, whose exact name is not known, 

 attacks red-gram, the female fly piercing the pods with its sharp 

 ovipositor and laying eggs singly inside their skin. The maggot 

 on hatching feeds on the seeds inside the pod. Sometimes more 

 than one maggot is found in a single pod, the only outward sign of 

 attack being the minute ami almost invisible hole through which 

 g was thrust. When full-fed the maggot pupates inside the 

 pod and after a few days emerges as a minute shining black fly. 

 This pest is kept in check by parasites, and no remedial measures 

 can be suggested at present. Another species of Agromyza attacks 

 cowpea, lablab and green gram, the larva; boring into the stem 

 and the plants so attacked withering. This fly is sometimes a 

 serious pest of young plants. 



The Cecidomyiadae form a family of Hies comprising a large 

 number of minute species, manj of which have earned notorious 

 reputations in other countries as crop-pests, but few have been 

 noted hitherto to do damage in India. Two species, however, have 

 lately been discovered at Coimbatorc, one of which (a species of 

 Contarinia apparently very near the West Indian C. gossypii, 

 but distinct) attacks the buds of cotton-plants into which the 

 larva bores so that the buds drop off and fail to mature; the 

 other, which may be called the Gingelly Gall-fly in the absence of 

 .m exact determination, attacks young gingelly capsules and 

 prevents their proper formation in a similar way, a wrinkled twisted 

 u.ill being produced instead of a fruit. It is probable that further 

 work will bring to light many more destructive species of 



