10 Jan., 1919.] Apple Culture in Victoria. 29 



APPLE CULTURE IN VICTORIA. 



(Continued from page 658, Vol. XVI.) 



By J. FarreU, Orchard Supervisor. 



Apple Root Borer {Leptops Hopei) — continued. 



The trap is made by placing on the stem of the affected tree, say, 

 9 inches above the ground, a strip of zinc, tin, or other such material 

 about 6 inches wide and of sufficient length to encircle the butt and 

 slightly overlap. The material should be cut in such a way as to 

 form a crinoline when placed on the stem and nailed in position. The 

 upper rim should fit closely on the bark, and the slope of the cone 

 may form an angle of about 45 degrees to the vertical or line of the 

 stem. When the zinc is being cut into the required shape a circular 

 hole about an inch in diameter is made near the upper edge to act as 

 an opening close to the bark Avhen the crinoline is in position. A. 

 canister about 5 inches long and 1| inches in diameter, made of 

 perforated zinc with a close-fitting lid on top and a light trap-door 

 at the bottom, is fixed over the aperture. The beetles, both male and 

 female, on emerging from the ground, climb the stem, but as their 

 upward movement is impeded by the crinoline they find the aperture 

 and enter the trap. The beetles should be collected from the traps 

 every second or third day and destroyed by immersion in boiling water, 

 or they may be burned. A mode employed by some orchardists to 

 destroy the captured insects is to simply decapitate them and throw 

 their bodies on the ground. This method is to be deprecated, because 

 the impregnated females, which have arrived at the egg-laying stage 

 prior to being killed, often after death, emit their eggs on the soil. 

 Weather conditions being favorable, the young grubs hatch freely 

 from these, and descend to the roots. 



The light zinc collars or bands used on the stems during recent 

 years afford a simpler and less expensive means of preventing the 

 beetles from climbing up the trees. The collar is about 5 inches 

 wide, and the ends overlap each other by about 2 inches; it fits closely 

 on the bark, and is made fast by a nail driven through the overlap 

 into the stem. Although agile and proficient climbers, the Root 

 Borer beetles are incapable of surmounting the smooth surface of the 

 new zinc. Owing to the corrosive influence of the air on the zinc 

 the surface after a time becomes somewhat rough. A foothold is thus 

 offered to the insects, but this may be destroyed and a fairly smooth 

 surface maintained by lightly rubbing the zinc downwards with fine 

 emery paper, or by painting the surface with whiting, which, especially 

 when dry, yields to the pubescence of the feet. The beetles, persisting 

 in their attempts to climb over the bandages, linger around the butts of 

 the stems, whence they may be collected by hand and destroyed as ex- 

 plained. The most disastrous results caused by root borer are those 

 which follow the immediate planting of pest-infested virgin land after 

 being cleared. At least two years should elapse from the time of clear- 

 ing such land until planting commences, and it should be cropped in the 

 interim to insure the pest's eradication. 



Generally speaking, when orchards show the first signs of infec- 

 tion, only a few trees in different parts of the areas are found to be 



