172 Second Report on Economic Zoology. 
should bear their full weight, and I need only quote one extract 
from his paper: — “When thickly covered, the bark separates from 
the stem, and the tree ultimately dies in consequence.” 
An observation was made with regard to wind distributing this 
pest ; glass slips with grease were hung in trees neighbouring the one 
infested, and were found to contain fragments of the wool and the 
larvae of the coccus. 
Treatment. 
The great increase and loss from this coccus makes the subject of 
treatment a very important one, especially as erroneous statements 
have been made as to the impossibility of washes doing any good. 
An observer in Gloucestershire states that he had saved several 
trees in parks and gardens by “ scrubbing the trees with a hard 
scrubber in dry weather and spraying the trees with a mixture of 
petroleum, soft soap, quassia and water.” 
Mr. Gillanders destroyed the coccus by the following mixture : — 
“ Take about half a gallon of soft water, boil and dissolve about 
1 lb. of soft soap and 1 lb. of common soap, add a handful of 
sulphur and a pint of paraffin and about the same quantity of 
turpentine. Then add about four gallons of soft water to this 
mixture. Churn well together, and apply with a whitewash brush 
just as the larvae are hatching out.” 
Another plan adopted some years ago, said to be successful, is to 
bore three holes with an inch auger at about equal distance right 
into the centre of the trunk, about three feet from the ground and 
sloping slightly towards the root of the tree. Into these holes place 
as much flowers of sulphur as can be conveniently got in, and All up 
the holes with soft wood. This should be done in autumn. How 
this acts I fail to see, unless the sulphur permeates the sap and so 
kills the insects. Mr. Gillanders tried this with Chermes on Silver 
Firs with considerable success. 
From experiments I made 1 found paraffin emulsion destroyed 
the pest, especially when used early in September when the larvae 
were moving about. Better results still were obtained by caustic 
alkali washing in winter and early spring. The emulsion if applied 
with warm water is most effective. The trees should be sprayed 
twice at intervals of two days. 
This pest is not attacked by birds, and rarely by insect parasites, 
according to Mr. Newstead. 
All trees cut down should be barked at once and the bark burnt. 
