390 



SCIENTIFIC NEWS. 



[Oct 12, l{ 



reach, if the conditions are favourable. When they attain 

 the allotted term of caterpillar life, or food fails, or becomes 

 unsuitable, they let themselves down to the ground with 

 silken cords and bury themselves from two to three inches 

 beneath the surface, making cocoons of particles of earth 

 bound together with silk. This takes place usually m the 

 first or second week in June. Towards the end of October 

 the moths begin to appear, and may be seen throughout 

 November and even through December, if the weather is 

 mild. 



Methods of Prevention in Orchards. — In orchards, 

 that is, where fruit trees are planted upon grass land, after 

 an attack of caterpillars the grass should be fed off close, or 

 brushed off close. Strong liquid manure may be applied 

 advantageously, or water having paraffin oil in it, towards 

 the latter part of October. Dressings of lime, gas lime, or 

 soot might be put on thickly some distance round the trees. 



Lime, or gas lime, or soot, or other pungent materials put 

 on thickly close round each tree, so as not to injure it, would 

 for a time hinder the moths from getting to the trees. It 

 must be borne in mind that the possible area occupied by the 

 chrysalids is some distance beyond the boughs of the trees, 

 so that in old orchards where the trees are very large, 

 putting lime or other substances in lumps close round the 

 trees is the more feasible plan. 



After an attack like that of the last spring it is most 

 advisable to take active measures of this kind. Knowing 

 where the authors of the mischief are concealed, fruit 

 growers should take steps to make their summer lodgings 

 as unwholesome as possible. It should be remembered 

 that grass land around fruit trees, being undisturbed, 

 affords shelter also to other insects injurious to fruit crops. 



As plants naturally grow towards the light, so the female 

 moths instinctively go up the stems of fruit trees nearest 

 to them as soon as they are transformed. They cannot fly ; 

 they must, therefore, crawl up. If they are unscathed by- 

 pungent applications, or succeed in getting over circles of 

 hot lime or ammoniacal soot, their progress must be arrested 

 by means of obstacles placed round the trees. 



That which is put round trees for this purpose must be 

 fastened very tightly and closely to their stems, so that the 

 moths cannot get under it. 



Hay bands dipped in tar, or smeared with tar and cart 

 grease, or with Davidson's composition,* may be used for this. 

 Oilcake bags or manure bags are better, dipped in a mixture 

 of soft soap, without water added, or paraffin oil, or carbolic 

 acid. Calvert's carbolic soft soap would be also applicable 

 for this. 



American fruit growers, whose orchards are infested with 

 insects of similar habits, put guards of different constructions 

 round the stems of the trees. 



This guard consists of a girdle of tin and stout linen 

 fixed low down round the tree. The linen is sewn to a cord 

 which is firmly and closely fastened round the stem. To 

 the lower edge of the linen a circle of tin is tacked, three or 

 four inches wide, and of sufficient diameter to stand three or 

 four inches from the stem. The inside of the tin is smeared 

 with tar aud cart grease, soft soap and paraffin, or carbolic 

 soft soap, or some other offensive, sticky composition, to keep 

 the moths from going beyond the guard. Occasional exami- 

 nations must be made, and the composition renewed, if 

 necessary, from time to time. 



Before the spring comes the bark of the stem below the 

 guard should be well scraped, and soft soap and paraffin, or 

 carbolic soft soap, worked well in with a stiff brush, to re- 

 move any eggs which may have been deposited there by 

 moths in despair of finding their accustomed places. 



It should be said that these guards ought to be put in 

 working order in August, in order to keep back the cater- 

 pillars of the Codlin moth, Carpocapsa pomonclla, which go 

 up the stems of apple and pear trees, after they have come 

 from the apples which they have spoiled. This caterpillar 

 wriggles up the stem and changes to a chrysalis under the 

 bark. It has done enormous injury this year in most orchards. 



•"Davidson's composition" may be obtained of Messrs. Dickson, 

 Newton Nurseries, Chester. 



Methods of Prevention on Cultivated Fruit Land 

 (Fruit Plantations). — In addition to the guards and ob- 

 stacles prescribed for trees upon grass land, it is possible to 

 get at the chrysalids in fruit plantations by thoroughly digging 

 and working the ground all round the fruit trees with spuds 

 and prong hoes in October, as well as by digging in lime, 

 soot, and other caustic substances. After the ground has 

 been dug it should be knocked to pieces by means of prong 

 hoes. 



This is especially necessary in the case of filbert and 

 cob-nut trees, as it would not be practicable to put guards 

 round these. 



When filbert trees and cob-nut trees have been badly 

 attacked by the winter moth and its allies, they should not be 

 pruned until January, after the eggs may have been deposi- 

 ted. The larger part of these will then be cut away with 

 the wood that is pruned off, which should be removed and 

 burnt. 



The bark of apple trees should be to some extent removed 

 from the stems and large lower limbs beyond the fork, 

 and these should be well brushed over with soft soap and 

 paraffin, or carbolic soft soap. Pear, plum, and damson 

 trees should also have their stems brushed with offensive 

 compounds. 



The Second Group of Moths Injurious to Fruit 

 Trees. — -With regard to the second group of moths injurious 

 to fruit trees, it may be said generally that it is important that 

 the stems and large lower limbs should be denuded of their 

 rougher bark, and rubbed over with soapy or oily composi- 

 tions, mixed with paraffin or carbolic acid. 



In the case of the Lackey moth, its caterpillars change to 

 chrysalids under rubbish, grass, and clods near to the fruit 

 trees they have injured. As they do not go deeply into the 

 ground it is advisable to brush off grass and weeds 

 round the trees, and to rake up and burn all rubbish, also 

 to apply lime and other caustic materials. Digging and 

 hoeing are likely to be very efficacious upon cultivated land. 



The female moths of this group can fly, and some of them 

 place their eggs upon twigs and spurs of fruit trees in the 

 summer, where they remain until the spring. It would be 

 advantageous to throw finely powdered quicklime over and 

 up into the trees during the winter after an attack. This 

 should be done in a damp fog, not when there is a drip from 

 the trees, but with merely sufficient moisture to hold the lime 

 upon every part of the twigs and spurs. 



For mossy apple trees this treatment is admirable, as it 

 destroys mosses and lichenous growths, which harbour all 

 kinds of insects. 



It is obviously more difficult to use means of prevention 

 against the moths of the second group than those whose 

 females are wingless. Fruit growers must depend somewhat 

 more upon remedial measures in their case, and the experi- 

 ences of the last season have indicated several remedies 

 which proved more or less satisfactory, and will be described 

 later on in detail. 



Japanese Copper Mines. — The copper mines of Ashiwo 

 are situate in the mountains, about 30 leagues to the 

 north of Tokio, whence they are easily accessible by 

 railway. They employ no fewer than 4,600 workmen, 

 including those engaged in felling timber as fuel. Coal 

 can only be brought at a prohibitive price, and there is 

 reason to fear that the adjoining forests will soon be ex- 

 hausted, as they are cut down without system and without 

 replanting. The mines have been worked since the 

 beginning of the 18th century, and until lately have 

 belonged to the Crown, but have lately become the pro- 

 perty of an individual capitalist who owns several other 

 mines. In 1886 they produced 4,150 tons of metallic 

 copper, being a yield of about 4 per cent, on the ore. 

 The crude metal is conveyed to Tokio, where it is refined. 

 The ore is slightly argentiferous, yielding from 500 to 

 1,250 grammes of silver per ton of copper. 



