ESCULENT-ROOTED PLANTS.— THE TURNIP. 



191 



long, or longev, than any two of the other joints 

 taken together ; the remainder decreasing some- 

 what in length to the terminal one, which is 

 large and oyai. The flies, which appear in the 

 early part of summer, and deposit their eggs on 

 the young turnip plants, have probably survived 

 the winter under groimd in the pupa state, en- 

 veloped in their cocoon. Emerging from them, 

 as soon as the milder weather is confirmed, in 

 their winged state, the females immediately lay 

 their eggs, after which they very soon die. The 

 eggs appear, for the most part, to be placed 

 round the outer margin of the rough leaves. In 

 favourable weather they are hatched in a very 

 short time, and the young larvaa immediately 

 commence their attack on the plant. At first 

 these larvae are of a deep black colour, and, of 

 course, small size ; but they grow rapidly, and 

 in course of a few weeks attain their full dimen- 

 sions. In the course of their growth they change 

 their skin several times, and most of their moult- 

 ings are attended with a slight change in their 

 colour. After casting their last skin, they are 

 of a dark lead or slate-grey colour, paler beneath." 

 Mr Curtis states that they are sometimes green, 

 a colour which we never saw them assume, for 

 in general they are not liable to much variation 

 in this respect. Like most of the other larvae of 

 their tribe, when touched or in any way disturbed, 

 they coil themselves up and remain motionless. 

 When full grown, the larvae cease to eat, and 

 allow themselves to drop from the plant that 

 nourished them to the ground, in which they 

 usually bury themselves ; or they take shelter 

 among rotten leaves, moss, &c. When examined 

 after a short time, they are found to be com- 

 pletely enclosed in a cocoon composed of two 

 distinct layers of silk. The inner layer is of a 

 fine satin lustre; and when the cocoon is opened, 

 it appears as if it had been washed with a solu- 

 tion of silver. When the fly is fully matured, it 

 makes its exit by gnawing with its mandibles a 

 hole in one end. The larvae are known in dif- 

 ferent parts of the country by the names we 

 have given above. They often destroy the crop 

 entirely, and at other times very seriously injure 

 it, destroying the leaves either wholly or in part. 

 Some have asserted that they do not attack the 

 Swedish turnip; but this opinion is not borne 

 out by facts : nevertheless, they are less severe 

 upon them than on the other varieties. Many 

 remedies have been recommended for lessen- 

 ing their numbers : as to complete annihilation, 

 that is only a thing to be wished for, without 

 much expectation of its being realised. 



Brushing them off the leaves, by drawing a 

 light broom over the plants, has been recom- 

 mended. This recommendation is offered on the 

 presumption that they are unable to crawl on 

 the ground and recover their position ; but ex- 

 perience has shown us that they have the power 

 of locomotion sufEoiently strong to enable them 

 to ascend again when brushed off. Besides, as 

 they are produced in generations following each 

 other in succession, from August till near No- 

 vember, a frequent repetition of brushing would 

 be necessary during that period. Birds greatly 

 assist us in reducing their numbers, and heavy 

 showers of rain are of great service, while it 



points out to us a remedy in applying water 

 from the rose of a watering-pot held somewhat 

 elevated, that the force of the falling water may 

 be the greater. A fire-engine, or a powerful 

 garden-engine, may be brought to play upon 

 them with great advantage ; and, if wrought upon 

 the walks, a boy may be employed to direct the 

 nozzle, BO that the water may not be unneces- 

 sarily wasted on the spaces between the drills. 

 Lime-water is better than pure water; the trouble 

 of applying both is the same, and the difference 

 in expense next to nothing. The caustic pro- 

 perty of the lime-water will destroy them in vast 

 numbers; for falling upon them while young, and 

 particularly when they have newly shed their 

 skin, it is instantaneously fatal to them. Dust- 

 ing the leaves with powdered hot lime once a 

 day is very destructive to them, acting upon 

 their tender bodies even with more effect than 

 when applied in a liquid form. Catching the 

 perfect fly before it has laid its eggs is the next 

 most effectual plan ; and this can readily be done 

 by the aid of an entomologist's net, for they are 

 slow flyers, and do not take long flights at a 

 time. Each fly caught would prevent the com- 

 ing into existence of from 250 to 300 caterpillars. 

 Hand-picking the caterpillars would be very 

 wholesome advice to give a Chinaman ; butwhere 

 labour is high, and large breadths have to be 

 gone over, very unsuitable to the British culti- 

 vator. Old ducks and old fowls, as well as troops 

 of young ones — remedies recommended by most 

 writers upon rural affairs for more than a cen- 

 tury — in most cases verify the old saying, " The 

 cure is as bad as the disease." 



Ceutorhynchus contractus, the turnip-weevil, 

 closely resembling the Curculio pleurostigma, 

 fig. 47, is often found feeding upon young tur- 

 nip leaves in company with Haltica nemormm, 

 the turnip flea-beetle. It is a small insect, 

 scarcely 1 line in length, of a uniform black 

 colour, slightly tinted with metallic blue on the 

 elytra, the latter with punctured lines. 



Haltica nemorum. — The turnip flea-beetle, 

 fig. 66, is thus described by Mr Stephens in 

 " The Book of the Farm," 

 vol. ii. p. 73 : « The insect 

 which first infests the 

 turnip plant, and attacks 

 its seed-leaves, is the tur- 

 nip flea-beetle, Haltica ne- 

 morum, fig. 66, usually, 

 though improperly, desig- 

 nated the turnip-fly, which 

 is a very different sort of 

 insect. The flea-beetle is 

 a coleopterous or hard- 

 shelled insect, capable of 

 either penetrating the 

 ground or bearing a con- 

 siderable pressure." " It 

 is a small insect," says Mr 

 Duncan, " scarcely one- 

 eighth of an inch in 

 length. It is smooth, shining, and of a brassy 

 black colour, with a slight tinge of green, par- 

 ticularly on the wing-cases ; the antennas 

 black, with the second and third joints, and the 

 apex of the first, of a pale colour. The thorax 



Fig. 66. 



TURNIP PLEA-BEETLE 

 AND GRUB. 



