106 



during the entire season exceeding the gross receipts from the crop. 

 It is not always certain whether the destruction of all or a large part 

 of the crop is threatened ; in this case the grower should ensure the 

 safety of his crop by considering the destruction as actually threatened. 

 The author places the problem of parasitism in the same category. 

 Unless parasitism can be definitely foreseen to such an extent as to 

 render spraying unnecessary, the attitude of the grower must be that 

 of the business man who, knowing that the chances of his business 

 being destroyed by fire are remote, nevertheless insures himself against 

 such a contingency as a business necessity. The author purposely 

 omits any discussion of market problems, considering that the contin- 

 gencies of market values can very rarely be foreseen at the time the 

 grower must deal with his spraying problems and therefore should not 

 affect his efforts in taking care of his crop. 



Parks (T. H.). A Device for Sowing Grasshopper Poison.— JL Econ. 

 Entom. Concord, N.H., x, no. 6, December 1917, pp. 524-525, 

 1 plate. 



During a grasshopper campaign in Western Kansas in the summer of 

 1916, an instrument was devised that made it possible to scatter 

 poisoned bran mixture over a much greater acreage than had 

 previously been attempted and is recommended for future grasshopper 

 campaigns. It consists of a canvas bag, waterproof for preference, 

 strapped over the shoulder of the operator and fitted with a feeding 

 device consisting of a canvas sleeve 12 in. long, 13 in. in circumference 

 at the upper end and 8 in. at the lower end, which fits tightly over the 

 end of a swinging tube made of tin or galvanised iron. The tube 

 should be 28 in. long, 2| in. diameter at the upper end, and If in. at 

 the lower end. Over the opening at the lower end, two short wires are 

 bent in the shape of a U, crossing each other at right angles at exactly 

 the centre and about one inch below the opening of the tube, and 

 soldered together where they cross and to the edge of the tube. This 

 causes the mixture to scatter evenly and thinly, and is of the correct 

 dimensions for applying 20 lb. to 4 acres. Oranges and lemons used in 

 the mixture must be ground through a food grinder in order to prevent 

 the tube from becoming stopped by the peelings. It was estimated 

 that 75 to 90 per cent, of the grasshoppers were killed by one 

 application of the poison bran mash scattered by means of this 

 apparatus. 



Pemberton (C. E.) & WiLLARD (H. F.). New Parasite Cages. — Jl. 

 Econ. Entom., Concord, N.H., x, no. 6, December 1917, pp. 525- 

 527, 1 plate. 



Certain improved cages that were used for confining Braconid 

 parasites of Ceratitis capitata (Mediterranean fruit-fly) have given very 

 satisfactory results and are here described. They consist of boxes the 

 bottom and one end of which are of wood, both sides and the other end 

 being of fine copper screening and the top of glass, fitted to slide free 

 from the cage for cleaning. In the wooden end a small opening or 

 door is cut ; this is sawed from the piece of wood composing the end 

 of the cage, the cut sides of the door being padded with thin strips of 

 cardboard tightly glued on. The cages used were 7 inches by 3 by 2. 



