270 INSECTICIDES, FUNGICIDES, AND WEED KILLERS. 



tected in the North of France and in Herault, but also the gardens 

 which in the spring time suffer much from the hibernating cater- 

 pillars of the Xoctua which attach themselves to the young shoots, and 

 cut the stems of small plants. They escape search and sight, because 

 they hide during the day, and only commit their ravages at night. 

 Fletcher, the Canadian Government entomologist, advists for the de- 

 struction of grej'-worm the use of a mixture of bran and emerald 

 green. The wheat bran which is used in the mixture is previously 

 moistened and sugared, then spread between the I'ows of transplanted 

 plants. As soon as the poison is on the soil, the plants are not 

 attacked by the grubs, which take themselves off rapidly, or die of 

 eating it. 



Cheimafobia brumata, L. (winter moth, Evesham moth). — The grub 

 of this butterfly, which is particularly injurious in the spring to the 

 buds of apple-trees, pear-trees and plum-trees, is overcome by cupro- 

 arsenical bouillies sprayed on the buds and the young shoots. This 

 process used for a long time in America, and recornmended by Eiley, 

 has been popularized in France by Prof. Debray of Alger, and Gros- 

 jean, inspector-general of agricultural education. 



Pieris Bajjce, L., Pieris Brassicce (white cabbage butterfly). — Cupro- 

 arsenical bouillie, spread on the cabbages, is generally used to destroy 

 the caterpillars. The rains suffice to wash the cabbages and render 

 them fit for food. 



Hadena Brassicce (noctua of the cabbage). — A mixture of gypsum 

 and emerald green dusted on the cabbages gives good results. 



Leucania Unijninctata, Haw. — Fletcher advises to sprinkle 

 meadows with a mixture of 1 lb. of emerald green and 25 lb. of 

 farina. 



Acari. — Amongst the phytoptides may be quoted Eriophyes Bibis, 

 Nal., or Phytoptus Bibis. In America it is overcome by spraying with 

 0-06 per cent emerald green, 0-12 per cent of wheat starch or soft 

 soap. The first spraying is made in spring, the second in autumn 

 shortly after the fall of the leaf to prevent the acari from taking 

 shelter in the buds. 



97. Copper Arsenite, Cu^As^Og. — Preparation. — I3y precipitat- 

 ing a solution of arsenite of soda by a solution of blue vitriol. The 

 green precipitate which forms, filtered, washed and dried, is known 

 as Scheele's green. To prepare an insecticidal and anticryptogamic 

 bouillie Gaillot recommends to dissolve 1 lb. of white arsenic and 1 

 lb. of soda ash in a gallon of boiling water and then to add with con- 

 stant stirring a solution of 10 lb. of blue vitriol in 10 gallons of 

 water. There is then added a milk of lime, made from 10 lb. of 

 lime and 10 gallons of water, then a solution of 20 lb. of molasses in 

 2 gallons of water ; the whole is then diluted to make 100 gallons of 

 bouillie which is nothing less than a bouillie bordelaise containing a 

 little Scheele's green. 



Properties. — Scheele's green is insoluble in water ; when it is 

 freshly prepared the precipitate is so fine that it remains a long time 

 suspended in the liquor, which is not the case with the dry commercial 

 product. 



