66 



INJURIOUS INSECTS AND FUNGI. 



[Sept. 1894. 



Thousands of acres were sown three times, and the plants were 

 cleared oft' as fast as they appeared. If dry weather sets m 

 soon after turnips have been sown, it often happens that the 

 " flea " clears them oft* as fast as they come up, but when 

 showers follow the sowing, the plants grow away generally 

 from the attacks of this insect. 



The turnip-beetle is only about one and a quarter lines in 

 length. It is black, with a yellow band on each wing-case. 

 Its wings are very long, and expand more than a quarter of 

 an inch> enabling the insect to take long flights to congenial 

 food. During the winter the insect remains in beetle-form 

 under clods, tufts of grass, and weeds, on the outskirts of 

 woods and by the sides of fields, hedges, and ditches. When 

 spring arrives, it is sustained upon wild cruciferous plants, 

 such as the wild-radish, hedge-mustard, and particularly char- 

 lock. As soon as the turnips are up, the beetle begins to feed 

 upon them, and lays eggs on the under sides of their leaves. 

 In about ten days little yellow larvae come from the eggs 

 and burrow into the leaves ; after living upon them for about 

 six days they fall to the ground and assume the pupal state, 

 in which they continue for about 11 days, and then change to 

 beetles, which again attack the turnip-plants. Several genera- 

 tions are evolved during the summer in favourable circum- 

 stances. 



Prevention. 



Sowing turnip-seed upon a " stale furrow " tends to prevent 

 the attacks of the beetle, or to diminish their severity, because 

 a " stale furrow " implies what is known as a " good season," or 

 a fine tilth, in which the plants grow quickly, whereas land 

 freshly ploughed up does not, as a rule, work down well, but is 

 cloddy. Moisture evaporates much more quickly in cloddy 

 ground, and beetles object to moisture, which also makes the 

 plants grow quickly out of their way. 



Turnip-land should be rolled down immediately after the 

 drill ; as this operation levels the ground and keeps in the 

 moisture, thus enabling the plants to come away rapidly. 



Most farmers drill manure with ashes, or mould, with the 

 seed, so that it may be close to the young plant and help it 

 along. The ashes and mould should not be too dry. 



It is most important to sow plenty of seed, and to take care 

 that it is of good germinating power. 



Cruciferous-weeds, such as charlock, must be kept down as 

 much as possible. It has been noticed that the beetles are 

 more plentiful in places where charlock has been abundant 

 in crops. 



Remedies. 



Dressings of soot are frequently very useful when the beetles 

 are thick upon the turnip-plants. Lime and soot, mixed in the 



