436 l-KOCEEDI.VGS OF THK THIRD EXTOUOLOGICAL MEETINO 



habits. The rice leaf-hoppers are attracted to light whilst the Delphacid 

 leaf-hoppers are not. The Delphacid leaf-hoppers develop fast in a 

 damp and moist atmosphere whilst the rice leaf-hoppers require hot 

 sunny days to reach their maximum development. The Delphacid 

 leaf-hoppers, like the rice leaf-hoppers, lay their eggs in the issues of 

 leaves. The nymphs on hatching out remain on the leaves sucking, 

 the juice and exuding the honey-dew which accumulates on the lower 

 leavft^. The nymphs as well as the adults aie extrtmely agile and with 

 the least disturbance jump off from plant to plant. With the break 

 in the rains in the middle of September 1915, the Delphacid leaf-hopjers 

 perished in hordes and were largely parasitized by a Dryinid. nnvu^e- 

 rable nymphs of the Delphacid leaf-hoppers could be seen with dark- 

 castaneous to blackish ovoid sacs either on the meso and meta-pleural 

 regions or on the penultimate segment laterally. When parasitized by 

 the Dryinid, the nymphs became sluggish in their movements. They 

 were then to be seen either moving about awkwardly on the leaves or 

 jumping off short distances only. When the parasitic grub becomes full- 

 fed, the sac containing it dehisces longitudinally and a whitish legless 

 Dryinid grub comes out. It moves about a httle or rests on the spot it 

 came out of the sac and begins spinning a thin hammock-shaped cocoon 

 within which it spins another, ovoid in shape and consisting of firmer 

 texture than the outer one. From such a cocoon the adult Dryinid comes 

 out by biting a circular hole with its strong mandibles. On emergence 

 the adult is very active and flits about the fields infested by the Del- 

 phacid leaf-hoppers. In fact the Drjdnid was responsible for the destruc- 

 tion of a large number of Delphacid leaf-hopper n3^mphs. The nymph& 

 seemed to be the special victims as in no case could I see a parasitized 

 adiilt. An examination of a large number of paddy fields in the infested 

 area in the Bilaspur District of the Chhatti.'garh Di%asion, Central Pro- 

 vinces, showed that a large number of pupse of the parasite were to be 

 seen on the infested plants. With the disappearance of the Delphacid 

 leaf-hoppers the Diyinid parasite also disappeared. The two pests 

 preceding the leaf-hoppers were destroyed to a large extent by the use 

 of field bags, by squirting kerosine in the infested fields and drawing a 

 rope across the fields so as to get the nymphs as well as adults in contact 

 with kerosine on the water. The cultivators also bagged their fields 

 with (^Jioties turned into temporary bags, previously moistened with a 

 little kerosine. 



The appearance of the infested fields. 

 The infested fields appeared blighted. In the year when the leaf- 

 hoppers appeared early, when the paddy plants were hardly above the 



