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lence of the Phylloxera, and they speedily decay. The insect first attacks 

 the surface-roots, and, when these are exhausted, migrates to those which 

 are larger and deeper seated. They prefer the angles formed by branch- 

 ing roclts, and lay their eggs in curved lines by swinging round their 

 abdomens. Planchon saw one lay 30, Eiisler 42, and Signoret 200, which 

 hatched in from two to three days. Unlike the parent, the young Phyl- 

 loxera is very active, and runs about till it finds a suitable spot on 

 which to begin sap-sucking. It now rapidly changes its skin ; how 

 many times is uncertain. But the oak Phylloxera, its nearest relation, 

 changes four times. 



They begin to lay eggs when from eight to fifteen days old, different 

 observers not agreeing as to the exact time. The yellow color of the 

 living insect changes when dead to a light brown, as also the eggs, 

 and when destroyed by carbon disulphide it becomes a dark gray, almost 

 black. By the loss of sap, perhaps also by the effect of a poisonous 

 excretion introduced into the wound made by the trunk of the Phyl- 

 loxera, the vine is injured. If but few are present, or if it is endowed 

 with strong powers of resistance, like the American vines, the presence of 

 the enemy will hardly be noticed. But if they increase, as usual, by the 

 second year the vine will show that it is diseased. The leaves turn yellow, 

 the stock becomes spindling, the shoots wither, the berries shrirel, and, 

 finally, the whole plant dies. Oftentimes the insects will be found to have 

 abandoned the exhausted roots of the dead vine for the more juicy 

 ones of surrounding vines, which have not yet shown decided symptoms 

 of attack. When one locality is exhausted, the insect removes to an- 

 other, partly by the cracks in the ground,* and partly by running over 

 the surface, and also in the winged form. According to observations 

 made at Klosterneuburg, it seems possible that this change may be 

 brought about by want of sufficient food. When winged, the wind is 

 an efficient agent for their distribution. Of course, the wingless form 

 may be transported in cuttings, stakes, straw, &c., and even in the 

 clothes of vine-dressers. Most energetic measures have been taken to 

 prevent the spread of the insect from Klosterneuburg and vicinity. All 

 the vines have been dug up and, with the roots, carefully burned, and 

 the ground fully impregnated with carbon disulphide by means of holes 

 bored three feet deep and six feet apart, in which fifty-five to one hun- 

 dred grams of the disinfectant was placed. It was found, on exam- 

 ination, that roots lying six feet deep in loamy soil were infested with 

 the insect. The penetrating character of the carbon disulphide is shown 

 by the fact that vines six feet from the holes in which it was applied 

 died immediately. April is the best time for operations, as the insect 

 is then soft and tender ; but from August to October the winged form 

 must be guarded against. Experience shows that, once cleared of the 

 pest, ground may be again planted with vines, which grow luxuriantly 

 without danger until it is re-introduced from a foreign source. 



Since the destruction of the vines entails great loss, efforts have been 

 made to discover some other method of getting rid of the insect. 



Of all the substances hitherto employed which do not injure the vines, 

 I)hosphuretted hydrogen and ammonia, liberated in the soil, have been 

 most successful. To use the first, a hole is bored in the ground and 

 filled with lime, on which water impregnated with phosphorus is thrown, 

 and immediately covered with earth, all openings near being also closed 

 in the same way as soon as steam is seen to issue from them. Among 

 other experiments, the effect of dynamite in loosening a refractory sub- 



* The absence of such cracks iu sandy grouud is probably the leas m why th3 insect is 

 cot found therein. 



