120 VEGETABLE GARDENING. 



in taking in fresh ground all the turf should be buried 

 and rotted down the first year, to avoid harbouring 

 the pests and carrying them over to another season. 

 The same remedies apply equally to both insects. 



Treatment. (1) Apply a liberal dressing of freshly- 

 burnt lime in winter not that lime kills the pests, 

 but it hastens the decay of grass roots and other 

 materials on which they feed. (2) Dig in naph- 

 thalene as a soil fumigant. (3) Apply a liberal 

 dressing of superphosphate before sowing or plant- 

 ing, and also use sulphate of ammonia. These 

 fertilisers have the double effect of driving off the 

 pests and inducing a strong, rapid growth in the 

 crop. (4) Carbon-disulphide may be used as a soil 

 fumigant in spring before planting or during the 

 growing season, so long as it does not come into 

 direct contact with the roots of plants. The fumes 

 of this substance are heavier than air and penetrate 

 downwards into the soil, so that it need only be 

 placed near the surface. A good plan is to fill a 

 clean oil-can with the chemical ; make a large num- 

 ber of small holes two or three to each square yard 

 3 inches deep ; squirt a few drops of the carbon- 

 disulphide into each hole, and immediately fill up 

 with soil. It must be remembered that this sub- 

 stance is both poisonous and very inflammable. 



Surface Caterpillars (Agrotis sp.). These cater- 

 pillars attack the plants at, or just below, the surface 

 of the soil. They attack nearly all garden crops, but 

 are particularly destructive to green crops. 



Treatment. (1) Promote a strong, rapid growth in 

 the plants by the use of sulphate of ammonia. 

 (2) Soot, or soot and lime mixed, placed round the 



