80 REPORT ON THE PADI-BORER. 
In confinement these flies live from four to five days. I have 
not been able to observe the method in which the fly gets at 
the padi-borer to lay its egg, or young, as the case may be; but 
it is probably when the latter leaves one joint of the stalk in 
search of more food that the fly effects its purpose. 
Effects on the Crop. 
As I have already stated, the first brood of caterpillars 
matures before the rice has made any stalk, and that its food 
consists of the midribs of the leaves and the growing 
shoot. This leads to the death of those young shoots which 
are infested by the borer. The next brood which pass their 
lives inside the stalk are those which cause the abortive ears 
of rice, and are, therefore, the most destructive to the crop. 
Though the first brood by killing the growing shoots of course 
do very_considerable damage. 
In the letter I have already quoted, Dr. LEECH has given 
his experience in the Krian district, and from what I have 
seen in Larut, nearly as much loss has been inflicted on the 
crops here. 
Preventive Measures. 
By the Malay way of harvesting, only the ears of the padi 
plant are cut, and the straw is left standing in the fields until 
the next planting season comes round. Hence all the cater- 
pillars and chrysalides have an opportunity of maturing and 
continuing the species to the next season's crop. 
The perpetuation of the race from one season to another is 
undoubtedly carried on through the self-sown rice and the 
lateral shoots of the old plants, though it is possible that 
some large stemmed grass may play a minor part in the 
matter. 
I found, six weeks after the harvest, in this district, that the 
straw was swarming with caterpillars of all ages; and I was 
informed by the Malays, that the shoots of the old plants and 
the self-sown rice, would continue alive until the land was 
broken up again for the next planting; so that food is avail- 
