OF THE STATE ENTOMOLOGIST. 57 



reach the lice. The simplest method of applying the sulphuret or 

 bi-sulphide, is by making three holes, two or three feet deep, around 

 the foot of the vine, then quickly pouring in the liquid and plugging 

 them up. The holes maybe made by a pointed bar driven by a maul 

 About two ounces of the liquid to each of these three holes are 

 recommended. 



Soon after the announcement of this method, I employed it as 

 a test on three vines which I knew to be infested with Phylloxera, 

 using 3 02. to the first, C oz. to the second and 9 oz, to the third — the 

 soil being a light clayey loam. At the end of 12 days I found plenty 

 of living lice on the first and second vines, and such were found long 

 afterward, though in small numbers, up to the time of the freezing 

 of the ground. On the third vine all the lice were evidently charred, 

 but the vine was also evidently injured, as the leaves wilted as though 

 they had been scorched, though whether from the vapor issuing from 

 the ground or from the injury to the root, it was impossible to deter- 

 mine. I think, however, from the former, as the larger roots were yet 

 alive late in the season, and the vine seems at this writing to be liv- 

 ing. After very careful and laborious experiments made in France at 

 different points and on different kinds of soil, by a commission espe- 

 cially charged with studying the action of this chemical, under the 

 method proposed by Messrs. Monestier, Lautand and d'Ortoman, it 

 fails to fulfill the sanguine expectations of these gentlemen. The 

 liquid is costly, its application is laborious, and there is great difficulty 

 in reaching and Idlling all the lice without injuring the vine. Great 

 caution must also be had in its use, as it is extremely volatile and ex- 

 plosive — the vapor igniting at a great distance from the vessel contain- 

 ing it. 



While, therefore, not very satisfactory results have followed the 

 use of pure insecticides, the application of fertilizers intended to in- 

 vigorate the vine and at the same time injure the lice, has been more 

 productive of good. Especially has this been the case with fertilizers 

 rich in potassic salts and nitrogenous compounds, such as urine. Sul- 

 phuret of potassium dissolved in liquid manure; alkaline-sulphates^ 

 with copperas and rape seed ; potassic salts, with guano ; soot and cin- 

 ders, are, among other applications, most favorably mentioned. 



Range of the Insect in America.— As already intimated, the insect 

 is indigenous to the North American continent. I have been able to 

 trace its existence, with absolute certainty, as far back as 1834; for in 

 the herbarium of Dr. Engelmann there are specimens of Viiis motiti- 

 cola Buck, which were gathered that year in Texas by the botanist 



5 — E R 



