TEOCEEDINGS OF THE THIED ENTOMOLOGICAL MEETING 381 



of the other borers as it has no horny process or hairs at the hind end 

 which has a hump-like protuberance on the dorsal side, 



Scirpophaga xanthogastrella {auriflua). 



Plate 41 and Plate 42, fig. 1. 



Foodplants — Sugarcane ; kanra {Saccharmn arundinaceum) ; batri {Sac- 

 char um spantaneiim batri). 



This insect is active from about March to October, the winter bem<T 

 passed in hibernation in the larval state on the foodplants. The hiber- 

 nating larvae emerge as moths in large numbers about March and the 

 two sexes appear practically in equal numbers. Out of a lot of such 

 larvae collected in February, 114 moths consisting of 58 males and 56 

 females emerged between 3rd March and 5th April. During the active 

 season the life-cycle takes about 6 to 7 weeks, viz., egg 1 week, larva 

 4 to 5 weeks and pupa about 1| weeks. Unhke the moths of other 

 borers, which are dry-grass colour and therefore inconspicuous on plants 

 or on the ground, the moths of this borer are perfectly white and con- 

 spicuous creatures which can be observed flying about in the fields and 

 ovipositing. 



Eggs are deposited mostly on leaves in a cluster which is covered 

 with bro\\Ti hairs from the anal tuft of the female moth. These brown 

 clusters are prominently visible on green leaves. The eggs are flattened, 

 scale-like, and overlap one another in the cluster. They are pale yellow 

 in colour and become dark grey before hatching, when the embryo is 

 visible coiled inside the shell. 



The newly-hatched larva is about 2-5 mm. long, slightly flattened in 

 shape, with the head shiny black, the prothorax entirely covered by a 

 black shiny shield,the next two thoracic segments dark smoky in colour, 

 the first abdominal segment pale yellow and the rest of the body brownish- 

 grey. The hairs on the body are longish and there are five pairs of 

 short prologs. 



Unlike the growTi-up caterpillars, which are extremely sluggish, and 

 helpless when taken out of their tunnels in the foodplants, the younf' 

 larvae are very quick and active. They issue out of the hairy covering 

 of the egg-cluster and walk about briskly on the leaves, some letting 

 themselves down by means of silken threads, and are thus blown hither 

 and thither on to neighbouring shoots. They disappear into the rolled 

 base of the top leaves and form the characteristic tunnel downwards 

 through the growing bud, thus killing the growing point and producing 

 " dead heart." If the larva is now taken out of the tumicl it cannot 

 form a fresh one even when placed in a suitable situation at the top 



