KATS IN Sugar-Cane. 57 



driven into their buirows by the fire and an attempt was made to dig 

 them out. The majority of the holes were found to be lodged among 

 the roots of the cane, consequently it was impossible to dig out the rats 

 without injuring the roots to a certain extent. The burrows were by 

 no means deep and were easily opened up. In nearly every case one 

 or more rats were found at the bottom of each burrow and in some 

 cases as many as ten were found in one hole. The rats were dazed and 

 stupefied by the fire and were easily caught and destroyed. 



Thus we have here a comparatively simple means of getting this 

 pest under control under the present conditions. The planters could 

 burn off just enough cane early in the morning to sufiice for the day's 

 cutting. After the cane has been cut the natives could be set on to 

 dig out and destroy the rats on the piece of land just cut. It would be 

 inadvisable to leave the destruction of the rats till next day for from 

 observations made it would seem that the great majority of the rats, 

 if not all, trek overnight from the field that has been cut into the 

 neighbouring standing cane. 



From the planters' point of view there are two objections to this 

 measure. First the roots of the cane are somewhat injured by the 

 digging, and secondly labour is scarce and difiicult to obtain. But the 

 need for some such remedy is desperate, and the present writer is con- 

 vinced that the loss entailed by the damage to the roots and cost of 

 labour will fully be set off by the increased crops obtained. 



The expense and trouble of the suggested remedies are surely 

 justified in the case of a pest which causes such heavy losses as the 

 present one, amounting to 75 per cent, of the crop or more on at least 

 two of the farms visited. 



The planters are very keen on the idea of a virus which will start 

 an epidemic among the rats and eventually wipe them out. Nothing 

 could be better, provided such a virus could be found. In the first 

 place, although several viruses have been put on the market at various 

 times, seldom have any of these proved satisfactory. The rats in the 

 trenches in Flanders were congregated in large numbers over small 

 areas, were mostly ravenously hungry, and were easily induced to take 

 the baits offered. Under these conditions the use of a virus proved 

 very effective, but it is extremely doubtful whether the same effects 

 would be obtained by the use of a virus in the cane fields. In the 

 second place, it is very difficult to obtain fresh virus in South Africa. 

 The writer made inquiries of most of the big dealers in agricultural 

 supplies in Pietermaritzburg and Durban, and only from the Union 

 Commerciale was he able to obtain any at all. The latter firm had 

 only two tubes in stock and these were generously placed at the 

 writer's disposal for experimental purposes. This meagre supply was 

 all used up at Umfolozi with the results detailed above. Thus it 

 would seem that the planters' hope of the pest being overcome by the 

 use of a virus is doomed to disappointment, and that some such 

 measures as those discussed in this article will have to be adopted, 

 troublesome and expensive though they seem. 



