1873] PHYLLOXERA VASTATRIX. 5 



drier, and here there was an abrupt limit to their extension. On the 

 worst affected roots not one was found beyond the arch, in which case 

 it is clear they had worked from the inside along the roots, but in all 

 cases did not move beyond the arches, proving that the insect does 

 not like cold and wet. Prompted by this observation, some pieces of 

 roots literally covered with the insects were steeped in clean soft water, 

 and they were all dead in from forty-eight to sixty hours. So that any 

 one receiving Vines who had any dread of this pest, would do well to 

 steep them in a tank for four or five days. AVe also found that three 

 hours' exposure to 4"^ to 0" frost effectually destroys it. Pieces of fresh 

 roots densely infected with it were also left exposed to the air in the 

 vinery, and in two d^js the insects were all dried up and dead. Eoots 

 were also done up in brown paper without any soil, and on them they 

 died in the same space of time ; in fact, seemed to evaporate. A few 

 drops of carbolic acid in a wine-glassful of water proved instant death to 

 them, and a very weak solution of Condy's fluid had the same effect. 

 In fact, everything that we have learned of this insect goes to prove 

 that it is easily killed when it can be got at. 



Numerous experiments have been tried to see if the insect would attack 

 or live on other fruit-trees besides the Vine. A Currant-bush and a Fig 

 were planted among the roots of the Amines on which it swarmed in 

 legions. These plants were allowed to remain for weeks, and they 

 pushed out quantities of young rootlets into the very centre of the 

 pest's strongest hold, but not one insect could be found adhering to 

 either the Currant or the Fig. A young Vine planted v.diere the 

 insect was not considered so strong was attacked by it in legions. 

 Pieces of Vine-roots coated with the pest were laid on a board, and 

 around them and touching them were placed fresh pieces of the roots of 

 the Peach, the Cherry, the Pear, the Gooseberry, Black Currant, and 

 Plum. The whole were covered with some soil, and a large bell-glass 

 placed over them, and left for fourteen days : at the end of that time 

 they were examined minutely through the microscope, but not one insect 

 had gone on to the roots of these fruits. On to a piece of Vine-root that 

 was put along with them in a clean state they did go. These experiments 

 go to prove that Phylloxera does not care so much for any of the fruits 

 named as it does for the Vine. On pieces of Vine-roots laid upon the 

 same board — not covered with soil, but merely covered with a bell-glass 

 — the insect was found quite shrivelled up and dead. Tobacco -smoke, 

 however strong, does not seem to affect the insect, for v/e placed it in 

 a glass vessel and filled it as full of tobacco-smoke as it could be, but 

 the insect remained alive. 



There are scores of decoctions that will kill this insect — such as salt, 

 hellebore, &c. ; but the difficulty to overcome lies in the depth of soil to 



