MR. MALCOLM DUNN ON PIlYLLOXFRA VASTATRTX. 
49 
XIII. Note on Phylloxera vadatrix. By Mr. Malcolm Dunn. 
[Mr. Bunn contributed last year (vol. iii., pp. 81 — 86) an account of the plan 
he pursued at Powerscourt for extirpating the Fhylloxera. The following 
remarks were addressed to a correspondent, and are extracted from *' The 
Gardener " of February last, pp. 63 — 64.] 
I AM very glad to hear that you have decided upon burning all your 
infected Vines and removing all the borders, and at the same time 
thoroughly cleansing every part of the houses, making sure that not 
a vestige of the insidious pest is left. Ey doing so you will have 
much more confidence that you have thoroughly stamped it out. 
Had I to deal with it again I would certainly deal with it in the 
same way, unless I had very special reasons for cleaning and 
saving the Vines, though I hope I may never have the task of 
dealing with it again. One attack from so dreadful a scourge is 
quite enough in a lifetime. By taking proper means, I have not 
the slightest doubt but that the very worst infected vineries can be 
effectually cleansed ; for with all my three years' experience of it, 
I never found that the insect lived more than forty-eight hours 
when isolated from the Vine. Indeed, in all the numerous experi- 
ments I tried in placing it on other plants than the Vine tribe, it 
never lived forty-eight hours ; but on the Vine it prospered and 
increased with amazing rapidity. I tried it on American varieties, 
such as Concord, Isabella, Sombruska, and the result was the same. 
There were Camellias, Azaleas, Cacti, Palms, Fuchsias, Pelar- 
goniums, &c., with various sorts of bedding-plants, in the vineries, 
and although their foliage in some cases was put amongst the 
infected Vine-leaves and their roots, in other cases running through 
their pots into the border amongst the infected Vine-roots, I never 
found an insect feeding on any plant except the Vine, and only in 
a very few instances did I find them trespassing on any other plant ; 
and when I did find them, I usually took them to my ofhce and 
placed them carefully under glasses, where I could watch them, 
and their life was always cut short within forty-eight hours. I 
tried to get it established on various vegetables and fruit-trees, but 
it would not feed nor live on tliem. There were Figs in the 
vineries, and the pest never touched them. Consequently my 
experience coincides with your own that the Phylloxera will not 
deposit its eggs nor live in any other plant but the Vine. 
With regard to the eggs, I have kept roots and leaves with 
eggs and live insects all through the winter ; but as soon as the,sap 
of the leaves and roots were exhausted, tlie eggs became shrivelled 
and never produced live insects. I took pieces of roots infested 
VOL. IV. E 
