150 



adults are found in large numbers in the stem and leaf -bases of plants 

 of Agave franheera that have not yet formed a pole. The insect 

 has also been found attacking A. vivipara, where it occurs only in the 

 " bull-end " of the flower-pole ; A. sisalana does not appear to be 

 attacked. The weevil has distinct potentiaUty for harm in locahties 

 where henequen cultivation is being started, and if, as is surmised, 

 the insect is introduced with planting material, such material should 

 only be obtained from locahties where the species does not occur. 

 The weevil, if once estabhshed, would be extremely difficult to control 

 and almost impossible to exterminate except by eradication of its 

 food-plants. It is j)ossible that some parasite may be found in Mexico 

 or Central America that could be transported with advantage to the 

 locahties where it has recently been introduced. 



Ballou (H. a.). An Observation on Ants. — Agric. News, Barbados, 

 xix, no. 462, 10th January 1920, pp. 10-11. 



A case is recorded of a house in Barbados that was seriously infested 

 with a small red ant, and although remedial measures were tried 

 for several months and the numbers were shghtly reduced, eradication 

 seemed impossible. A small colony of the crazy ant, Prenolepis 

 longicornis, subsequently became estabhshed in the house and at 

 the present time it is found all over the house, while the red ant has 

 entirely disappeared. 



Sanders (G. E.) & Kelsall (A.). The Use of White Arsenic as an 

 Insecticide in Bordeaux Mixture. — Agric. Gaz. Canada, Ottawa, 

 vii, no. 1, January 1920, pp. 10-12. 



As a result of three years' investigation on the various methods of 

 using white arsenic, a method of preparation is described which is 

 safe and simple and results in a product that compares favourably 

 with other more complicated and expensive forms of arsenicals. The 

 advantages of using white arsenic are its low cost, varying from 

 one-fifth to one-tenth per unit of arsenic over that of other arsenicals, 

 and its concentrated form. The disadvantages generally alleged 

 against it are the difficidty with which it mixes with water, its poor 

 physical condition, the low killing value sometimes reported for it 

 and its caustic action on foliage. These disadvantages can all be 

 overcome if the following method is carefully adhered to. The arsenic 

 used must be superfine, that is, guaranteed to pass a screen of 250 

 meshes to the inch. It is immaterial whether high calcium or dolomite 

 lime is used, though the former is preferred. To make 10 gals, of 

 copper sulphate stock solution the vessel should be filled with 10 gals, 

 water into which is sifted a mixture of 1 lb. white arsenic and 1 lb. 

 hvdrated lime. This should be thoroughly stirred and in it should be 

 suspended a sack containing 10 lb. crystal copper sulphate. The mix- 

 ture should be stirred occasionally while the copper sulphate is 

 dissolving. The solution should be made at least 24 hours before it is 

 used, and when made, it will keep indefinitely. It should be stirred 

 thoroughly before it is diluted. The poisoned Bordeaux mixture 

 made in this way will have the desirable physical characteristics of 

 ordinary Bordeaux mixture, while its fungicidal value is unimpaired. 



