184 APHIDES, SCALE INSECTS, ETC. 



found on the young shoots, and the leaves, and are 

 distinguishable by the white cottony material which 

 surrounds them. I have also found this kind of 

 attack on the rootlets. The piercing of the Aphis- 

 sucker causes the growth just below the bark to be- 

 come swollen and pulpy ; then the cells divide, and 

 the bark above splits, and thus openings are formed, 

 which give the Aphides new hiding holes ; and the 

 diseased growth from their punctures is continued, 

 until large tumour-like masses are formed, and the 

 trees are very seriously injured. 



The best method of checking attack is to keep the 

 bark of the Apple trees in such a healthy state, — by 

 means of proper pruning, and clearing away injured 

 branches, and useless and cracked bark (and other 

 measures), — that there may be as few cracks, and cran- 

 nies, and half-healed spots, as possible ; consequently 

 as little as possible of the shelter in which this Aphis 

 delights. Also, when the white wool in any nook, or 

 on any soft shoot in summer time, shows the presence 

 of the pest, the shoots should be at once cut off, and 

 some remedy should be well brushed or rubbed into 

 infested nooks. 



The number of different kinds of applications ad- 

 vised are almost beyond counting, though the principle 

 throughout is one. But anything will be of use which 

 will stifle or poison the Aphides, without hurting the 

 bark of the tree ; and probably common soft-soap, 

 ■or soft-soap with a little sulphur (lissoh'ed in it, or 

 paraffin or tobacco-juice added to it, and well rubbed 

 or washed in, so that it may be sure to reach the 

 pests in their sheltering nooks, will answer as well, 

 or better, than most of the many suggested appli- 

 cations. 



Some of the applications said to succeed should be 

 applied (if at all) with great caution, or they may do 

 more harm than good by soaking into the bark. Tar 

 is especially to be suspected, for it is apt to melt in 

 the heat of the sun ; and turpentine, resin, and fish- 



