Maskell. — Note on an Aphidian Insect. 15 



pass through alternate periods of illness and apparent health, and never be 

 really what they should he. At present we only know, as it were, the first 

 stages of the malady. 



I find no particular mention anywhere of permanent deadly injury done 

 by Chermes in England ; but we cannot judge with certainty from the ex- 

 perience at Home what might be the effects of such a parasite in a climate 

 like ours. 



As regards the methods of destroying this pest, it is not easy to suggest 

 any certain way, on account of the mechanical difficulty of getting at the 

 insect on branches of pine trees, covered so closely as they are with leaf 

 tufts. But, as the Homoptera all act in the same way, by sucking through 

 the setae of their rostra the juices of the plants they live on, I see no reason 

 why remedies already found useful as against the Coccidte should not be 

 efficacious against such an aphidian as our present insect. A great 

 number of experiments have been made in various countries with a view to 

 destroy Coccidfe. Some of these, which are applicable to deciduous orchard 

 trees, where the insect is easily approached as it lies on the bark (such, for 

 example, as the different oil mixtures, kerosene, etc.), are not available in 

 the present instance ; and, probably, the only way to attack our aphis 

 would be by spraying over the tree some liquid remedy. There are con- 

 stantly advertised in the newspapers compounds called " Scaly blight- 

 destroyers," and the manufacturers of these claim for them all sorts of 

 virtues. I believe, however, that in the majority of these the chief reliance 

 is placed upon such substances as sulphur, carbolic acid, etc., which are of 

 no real use. Sulphur, indeed, is an excellent remedy for such diseases as 

 oidium in vines, which are fungoid ; but it seems to have no sort of efficacy 

 as against homopterous insects. Tobacco is, in itself, most useful ; but 

 probably the cost in this country would be too great. But of all remedies 

 the best, according to the experience of American observers, appears to be 

 common soap. I find from Professor Comstock that a solution of a quarter 

 of a pound of soap to a gallon of water has been found to be of very great 

 efficacy in destroying Coccidse of all kinds, both on deciduous and evergreen 

 trees, on the bark and on the leaves. This being so, probably it would be 

 also very useful against the pine insect, and is well worth trying. Of 

 course any common soap would do if the solution is made strong enough. 



In some papers lately forwarded to the New Zealand Government by 

 the Colonial Office in London, I find a suggestion by a French gentleman 

 for destroying Phylloxera vastatrix (also a homopterous insect) by driving 

 copper nails into the wood of the infested vines. The idea seems to be 

 that the insects would imbibe some salts of copper, and so be poisoned* 

 Whether such a course would answer with pine trees and their aphidian 

 pest I cannot say. 



