Reports to various Correspondents . 91 
The apparent connection between the two is of some economic 
importance if, as seems essential, larch can only be infected from 
spruce. Should this actually be so, and I see no reason to doubt it, 
then it would be as well to give up mixed spruce and larch plan- 
tations, the two trees being grown apart and separated by intervening 
non-coniferous plantations. 
The Spruce Gall Aphis occurs in N. America. It is said to have 
been introduced with N. European and Norway spruces. It was 
described as Chermes abieticolens by Dr. Thomas in his Report for 
Illinois for 1879, p. 156, but was proved by Cholodkowski to be 
C. abietis . It is common in Continental Europe, occurring as far 
south as Parma. 
Treatment. 
With regard to treatment, all we can do is to wash the affected 
trees with paraffin emulsion for larch attack whenever we see the 
pest present, and for spruce when we observe the winged forms 
issuing from the galls, and in the spring just before the galls are 
beginning to form. Small trees should be gone over before the galls 
open and all such growths picked off and destroyed. These galls 
stunt and deform the trees when young, and should certainly be 
collected if we wish the plantation to develop into a good growth. 
Natural Enemies. 
Various Lady-birds feed upon the Spruce Gall Aphis (Scymnus, 
Coccinella ) and also the larvrn of Lace Wing Flies ( Chrysopa ). 
Numerous Spiders also feed upon them. 
The Ash and Willow Scale. 
( Chionaspis salicis, Linnaeus = C.fraxini, Signoret.) 
Frequent enquiries have been received lately concerning a scale 
on ash saplings. This scale is certainly very harmful to the 
saplings, but in no case can I find that they have caused the death 
of them. Some under observation close to my own house were 
literally covered with the scales, and yet kept alive. On the other 
hand their growth was decidedly checked. Certain clean saplings 
growing side by side with those smothered in scale were an inch 
more in diameter than the affected ones. 
This scale is said to inhabit the willow as well as the ash, and 
also to occur on alder, hawthorn, privet and lilac. To osiers it is 
