68 INSECTICIDES, FUNGICIDES, AND WEED KILLERS. 



per acre) iu emulsion with 100 kilogrammes of 4 per cent caustic 

 potash and 15 kilogrammes (13 "2 Ih. per acre) fish oil. The result 

 is not perfect, except after having renewed the treatment, the success 

 of the first injections only being momentar}-. 



Brocchi, as well as Mohi', have obtained excellent results against 

 Agriotes sputator by using capsules containing carbon disulphide. The 

 larvae of the Elaterides are very hardj^ and as they live mostly in the 

 upper layers it is advisable to make holes 20 centimetres (7"8 inches 

 deep) and run in a dose of 50 grammes of sulphide per metre, say 775 

 grains per 140 inches square. It would be advisable to roll the gi'ound 

 before treatment to consolidate it and prevent the sulphide from 

 evaporating too rapidly. Amongst the weevils there are several which 

 can be destroyed by carbon disulphide. 



Peritelus griseus ; Othiorhynchus sulcatus, Fb. (black vine weevil). 

 — Muller advises to make three or four holes per square metre round 

 -the tree and to distribute therein by the pal-injector a total dose of 25 

 grammes of carbon disulphide. Insects hidden underground should be 

 ■exterminated at the end of May, and the larvae during summer. 



Othiorhynchus ligustici, L. (Liveche's weevil). — Girard, Vergnete, 

 Lamothe, and Brocchi have shown that treatment with carbon 

 disulphide is most efficacious. 0. raucus, Fb., and 0. picipes, Fb. (clay- 

 coloured weevil), both injurious to fruit trees and vines, may be treated 

 in the same way. 



Bruchus Pisi, L. (pea-beetle). — This weevil passes its entire 

 evolution on the pea. Peas intended for sowing should be disinfected. 

 Eeh has observed that the treatment by carbon disulphide was in this 

 case as efficacious as hot water. It suffices to treat peas for twenty- 

 four hours in a closed vessel and to aerate them afterwards. This 

 same process is applied to Bruchus rufimans, Schonh. (haricot-weevil) ; 

 to Bruchus granarius, Payk fbean-beetle) ; Calanclra granaria, L. 

 (calender or wheat-weevil) ; Calandra Oryzce, L. (rice calender), and 

 Anohium jxmlceum (maize-weevil). The lai-vae of these weevils live 

 inside the grain and cause great ravages in granaries. The following 

 processes have been used to exterminate them. Spread on the floor 

 of the infected granary 1 litre of carbon disulphide (35-2 fl. oz.), pile 

 the grain in a heap on the drenched space, and cover it with a tent or 

 a cloth. The grain may also be spread in a closed chamber, in a layer 

 20-30 centimetres deep and 1-2 litres of sulphide per ton of grain to be 

 disinfected uniformly distributed thereon. The whole is covered with 

 sacks, and the sulphide allowed to act for twenty-four to thirty-six 

 hours. This method of disinfection has the drawback of being attended 

 by certain fire risks, and that is why it is done far from dwellings. In 

 that case a cask is used, which is filled with grain, then the carbon 

 disulphide is run in at the rate of 500 grammes (M lb.) per 100 kilo- 

 grammes (220 lb. of wheat). The cask must be closed, with its lid, so 

 as to roll it, first, shortly after closing and then a second time, twelve 

 to twenty-four hours afterwards. Nothing remains to be done but to 

 empty the grain, which is perfectly disinfected- (Pabst and Hollrung). 

 The bad taste imparted to the grain does not last long, and it rapidly 

 disappears if shovelled a few times, or if passed through the fanners. 



