Insect Pests and Fungoid Diseases. 419 



mass of excrement The Cabbage Moth, although chiefly a cabbage pest, 

 by no means confines its attention to that family ; there are very few 

 plants in the garden which altogether escape its ravages. 



Treatment : Spraying with paraffin emulsion or dusting with lime and 

 soot will check egg-laying ; a hot dry summer is favourable to the rapid 

 increase of butterflies and moths, and repeated sprayings in such a season 

 would probably keep the crop fairly free from caterpillars, but spraying must 

 cease before the cabbage begins to head in. After then, spraying with 

 water heated to 140 degrees is said to be effective, or sprinkling freely with 

 salt is said to kill the caterpillars without injuring the plants. 



On small areas hand-picking should be practised before the caterpillars 

 have left the outer leaves, and portions of leaves containing clusters of 

 eggs should be removed and burnt. 



CABBAGE ROOT FLY AND MAGGOT (Phorbia brassicceJ. 

 Cabbage Root Fly somewhat resembles the common house fly but is rather 

 smaller. It is a great pest to all members of the cabbage family and also 

 attacks cruciferous weeds. The female fly begins laying its eggs during 

 April and May, and there are probably two or three generations during the 

 summer. The eggs are deposited in cracks in the ground, as close to the 

 plant as possible In a week or more the maggots hatch out and burrow 

 first into the smaller roots, then into the larger roots, and finally into the 

 stem. Plants attacked are stunted, with yellow and shrivelled leaves, and 

 they rot off at the stem. 



Treatment: This pest is very difficult to deal with. Numerous pre- 

 ventive measures may be practised, such as fitting pieces of tarred paper 

 closely around the stem at time of planting or by mixing half a pint of 

 paraffin to a peck of sand and sprinkling this round the stems of the plants 

 weekly ; but as these measures to be effective must be carried out before 

 an attack it is quite certain they will not be adopted, at any rate in commer- 

 cial work, until the attacks of the pest become more serious and persistent 

 than at present. Probably if the ground was dressed just previous to 

 planting with one of the advertised soil fumigants it would have the effect 

 not only of clearing the soil of many pernicious soil insects but also of 

 repelling the fly and so keeping the crop clear of maggots. After planting, 

 a dressing of nitrate of soda, at the rate of one and a half cwts. per acre, 

 would make the ground somewhat disagreeable to the fly and would stimu- 

 late the plants to grow away from the pest. 



All plants which show signs of attack by turning a dull colour and droop- 

 ing should be at once pulled up and burnt. Bi-sulphide of carbon injected 

 in the ground near the plants will kill the maggots, but it must not be 

 allowed to touch the roots. 



When a crop has been badly infested, as soon as it is cleared the ground 

 should be dressed with fresh gas-lime at the rate of from two to four tons 

 per acre ; this should be ploughed in at once and the ground left uncropped 

 for three or four months. No cruciferous crop should be allowed to follow 

 and all cruciferous weeds should be rigorously kept down. 



