367 



The most effective fumigant is carbon bisulphide, especially if the 

 fumigating bin is air-tight ; the grain should be subsequently exposed 

 to the air to get rid of the fumes. The amount to be used depends 

 on the temperature ; at 60°-70° F., 1 oz. (two large tablespoonfuls) 

 is sufficient for 6 bushels of husked cobs, or 1 oz. to every 3 bushels 

 of shelled grain. In large quantities 1 lb. of carbon bisulphide is 

 required for 100 bushels of cobs. In fumigating empty spaces 1 lb. 

 liquid is enough for 100 cubic feet. At lower temperatures the quan- 

 tities should be increased by half, but at higher temperatures ^-f of 

 the amount stated will suffice. As the fumes are heavier than air the 

 liquid must be put in shallow vessels or on cotton waste on the top 

 of the grain to be treated. 



Hydrocyanic acid gas is a rapid and certain insecticide, but owing 

 to its being highly poisonous, it can only be used in a specially con- 

 structed fumigator. Naphthaline scattered throughout the stored 

 grain has proved a successful method of keeping seed maize, but if 

 the grain is to be used for feeding stock, it must be thoroughly aerated 

 to remove the odour. Other remedies are the exposure of the grain to 

 the heat of the sun, preferably on a black tarpaulin, a temperature 

 of 116° F. killing the weevils in 10 minutes ; the whitening of the walls 

 of the store with quicklime, and the placing of barrels full of it in the 

 corners to absorb all moisture ; coarse salt, kerosene and sulphur di- 

 oxide gas have been tried, but destroy the germinating power of the 

 grain. 



Green (W. J.), Selby (A. D.) & Gossard (H. A.). Calendar for the 

 Treatment of Plant Diseases and Insect Pests. — Ohio Agric. Exp. 

 Sta.. Wooster, Bull. no. 309, January 1917, 31 pp. 3 figs. [Received 

 19tli June 1917.] 



This bulletin contains a spray calendar, a synopsis of seed and soil 

 treatments, arranged alphabetically, and the formulae, methods of 

 preparation and directions for use of numerous fungicides and insec- 

 ticides. 



Whitmarsh (R. D.). The Green Soldier Bug, Nezara Maris, Say. — 

 Ohio Agric. Expt. Ski., Wooster, Bull. no. 310, February 1917, 

 33 pp,, 16 figs., 7 tables. [Received 19th June 1917.] 



This bulletin supplements a previous paper on Nezara hilaris (green 

 soldier bug) [see this Revieiv, Ser. A, ii, p. 704]. Further observations 

 continued during the years 1911-1916 lead to the conclusion that 

 climate is one of the most important factors in the natural control 

 of this insect, a winter ^vith sudden, wide variations of temperature 

 being more unfavourable than a very cold season in which the temper- 

 ature is uniformly low. A Hymenopteron, Trissolcus sp., probably 

 T. eiischisti, Ashm., which is an egg-parasite, also exerts a great 

 influence in holding this pest in check. 



Gossard (H. A.). Distribution of the Ohio Broods of Periodical Cicada 



with Reference to Soil.—Ohio Agric. ExjJt. Sta., Wooster, Bull. 



no. 311, March 1917, 22 pp., 14 figs. [Received 19th Jime'l917.] 



A most striking coincidence has been noticed between the maps, 



prepared by the author, showing the areas occupied by the most 



