THE APPLE-TREE BORER BEETLE. 63 



very few cases, however, will it be found necessary to 

 chop out any infected fruit tree, the practice of so doing 

 being an unnecessary one. 



The application of tar mixed with grease, as also white 

 lead and raw oil, has been recommended for use against 

 borers, by smearing or painting the trees ; and although I 

 have used both successfully against certain boring insects, 

 I should hardly care to advocate its general use, more 

 especially on fruit trees, but should prefer keeping a sharp 

 look out for signs, which are too well known to the prac- 

 tical fruit- oTower, and at once tackle the borer bv the 

 various means already indicated. 



Stopping the holes with wire has been suggested, but 

 owing to the high price of labour here its use in large 

 orchards would be next to impossible. 



The application of sulphur, tar, bisulphide of carbon, 

 or other fumes, by means of steam-power (providing the 

 machine can be produced at a price within the reach of at 

 least the large growers, and with some modification of 

 detail), would, in my opinion, be perhaps the most eflPective 

 of all methods, as the forcing of the steam would pene- 

 trate so far into the workings of the insects as to either 

 make their position altogether untenable or entirely 

 destroy them, grubs and all, to say nothing of its use- 

 fulness in distributing the Bordeaux mixture, and other 

 fungus-resisting compounds, to the resting spores of 

 fungi, as Fusicladium (or scab), Capnodium (or smut 

 fungus), Roestelia (or scab). Mildew, Oidium, curl in 

 peach, shot-hole of the apricot, black spot on grapes, and 

 other pests of the orchardist and vigneron. 



The habits of Scolytus destructor, or elm-beetle of 

 Europe, are somewhat similar to those of the " apple- 

 tree borer;" the principal economic differences being that 

 the workings of the " elm-borer" assume the shape of 

 irregular tunnels or burrows ; the insect, however, being 

 quite as difficult of eradication as the " apple-tree borer." 

 Whole avenues of magnificent elms in France and else- 

 where having had to l^e cut down and destroyed owing 

 to the attacks of these Scolytids. 



