66 SIXTH ANNUAL REPORT 



these brief inundations at that season, affect only the few lice near 

 the surface, and are by no means essential, they are nevertheless im- 

 portant auxiliaries to the more thorough fall or winter submersion, as 

 they destroy the few lice which are always invading a Vineyard in in- 

 fested districts. These summer inundations will be necessary only 

 after the winged insects begin to appear; and three or four, each last- 

 ing less than two days, made between the middle of July and the fall 

 of the leaf, will effect the end desired. (19) 4. An embankment should 

 be made around the vineyard in order that the water may evaporate 

 and permeate the earth, but not run off and carry away any nutritive 

 properties of the soil. 



The varied success which has attended the different attempts to 

 rout the enemy by inundation, is owing to the lack of thoroughness 

 in many of them. The ground must be thoroughly soaked for a suf- 

 ficient length of time. Temporary irrigation does not accomplish the 

 end, for the reason that it does not reach all the lice, and does not 

 break up the numerous air bubbles which form in the soil and prevent 

 the drowning of many of the insects. 



On our best hilly vine land, thorough submersion is impractica- 

 ble ; but on our bottom lands some of the grapes which fail now may 

 be made to succeed by its means. 



Of 140 different applications made by an intelligent and compe- 

 tent commission in the department of Herault, France, most of the 

 pure insecticides proved valueless. Many of them, such as carbolic 

 acid, oil of cade, arsenious acid, sulphide of calcium, sulphide of mer- 

 cury, arsenate of potash, etc., etc., will effectually kill the insect 

 when brought in direct contact with it; but in field practice they can 

 either not be brought in this direct contact, or else can not be used 

 strong enough to kill all the lice without injuriously affecting the 

 vine. Carbolic acid, added to water at the rate of about one per cent., 

 applied by pouring into deep holes made by a crow-bar or auger, has 

 given satisfactory results; and a thorough application of soot has alsa 

 been strongly advocated by those who have tried it. In the experi- 

 ments that 1 have been able to make in a small way, a thorough 

 mixing with the soil of a cheap carbolic powder, has given good 

 results. 



The latest insecticide that has attracted attention and given great 

 hopes in France, is the bi-sulphide of carbon. It seems to have been 

 used as early as 1869 by Baron Th^nard, but was brought prominently 

 before the public last autumn by Messrs. Monestier, Lautand and 

 d'Ortoman, who first proposed to introduce it at a great depth in the 

 soil, so as to utilize its vapor. A vapor will naturally have the advan- 

 tage over a liquid, as it will more effectually permeate the soil and 



