179 



larvicide, viz., 150 gallons carbolic acid, 150 lb. broken resin and 30 lb. 

 caustic soda, is a good mosquito larvicide but is ineffective against 

 house-fly larvae ; iron sulphate, unsatisfactory, larvicidal power 

 probably low ; sodium chloride, at the rate of 2^ lb. per gallon, killed 

 55 per cent, larvae, and somewhat reduced the number of bacteria ; 

 copper sulphate, 1 lb. per gallon, killed 67 per cent, of the larvae, 

 bactericidal power strong and injured the manure chemically, reducing 

 the amount of soluble nitrogen ; lime-sulphur, no larvicidal or 

 bactericidal power ; potassium cyanide, high larvicidal power, 

 solutions of '1 and '02 per cent, strengths, killed 93 per cent, larvae, 

 bactericidal action stimulating and no injurious chemical effects, but 

 its poisonous nature minimises its practical value ; Paris green, used 

 in suspension, killed 70-90 per cent, larvae, the strong solutions were 

 highly bactericidal, killing 50 per cent, bacteria, the weaker solutions 

 were stimulating, like potassium cyanide ; formaldehyde, larvicidal 

 power high, killed from 75-85 per cent, larvae, bactericidal power 

 high, chemically it increases the production of nitrates and ammonia ; 

 sodium fluoride, high larvicidal power, destroyed from 84-90 per 

 cent, larvae, but the cost (about Is. per lb.) may prohibit its general 

 use ; ammoniacal gas liquor, some larvicidal power, but also stronglv 

 bactericidal and the liquid form is not practically convenient ; calcium 

 cyanamide, used dry, a 20 lb. appUcation killed over 99 per cent, 

 larvae, average larvicidal power 58 per cent. ; this substance is expen- 

 sive, l^d. per lb., but its fertilising power as a means of adding nitrogen 

 to the soil may make it valuable ; borax, including sodium borate 

 and calcined " colemanite " or crude calcium borate, had a marked 

 larvicidal action and exerted no permanent injury on the bacteria, 

 nearly all trials showed a larvicidal power of over 99 per cent. ; the 

 borax not only kills the larvae but also exerts a toxic effect on the 

 eggs, which calcined colemanite did not. The minimum amounts of 

 borax and calcined colemanite which are effective are "62 lb. borax 

 and "75 lb. calcined colemanite to 8 bushels of manure in 2 or 3 gallons 

 of water. In applying the borax sift it round the outer edges of the 

 manure heap and then sprinkle 2 or 3 gallons of water over it ; it should 

 be appUed to perfectly fresh manure, because it is in that that the flies 

 lay their eggs. Borax may be applied in the same proportion to other 

 manures, as well as to refuse and garbage, also to floors, crevices and 

 street sweepings, and water should also be added. It is recommended 

 that not more than 15 tons per acre of borax-treated manure should 

 be applied to the field, because its effect has only been studied on a 

 few crops ; large amounts of borax are injurious to the growth of 

 plants, and its cumulative effect has not been determined. 



Gaver (F. van) & Peingault (E.). Contribution ^ I'^tude des Culi- 

 cid6s de la region marseillaise. [Contribution to the study of 

 CuLiciDAE in the neighbourhood of Marseilles.] — C. R. Soc. Biol, 

 Paris, Ixxvii, no. 26, 24th July 1914, pp. 401-402. 



The author has investigated the Cuhcid fauna of the neighbourhood 

 of Marseilles, chiefly by rearing out the larvae. The work was begun 

 at the end of April, but was constantly interrupted by sudden falls of 

 temperature, which killed large numbers of the larvae collected. 



