518 



cocoon, from which the adult emerges in 1 7 days. The leaves of banana, 

 bucare and sweet potato were also attacked. Euscepes {Cryptorrhynchus) 

 hatatae appeared during the winter in light, dry soil. Sweet potatoes 

 should not be left in the ground after they are full grown, neither 

 should they be planted in soil infested during the previous season. 

 Grevillea robiista (silk oak) was attacked by Asterolecanium pustiilans . 

 This scale forms pit-like depressions on the small branches. A lime- 

 sulphur spray will control it. Some damage to tobacco seed-pods by 

 Chloridea (Heliotliis) ohsoleta was noticed. The commonest weevil is 

 Diaprepes syengleri ; the adult has a variety of host plants and the 

 larvae have been reared from the roots of sugar-cane, orange and 

 sweet potato. On citrus trees, eggs are laid in masses on the upper 

 leaf surface, and are protected by the rolling over of the edge. After 

 hatching, the larvae drop to the ground. The attacks of the adult 

 may be controlled by arsenical sprays. 



Butler (0.). Notes on the Preparation of Bordeaux Mixture. — New 



Hampshire Agric. Expt. Sta., Durham, N.H., Circular no. 15, Mav 

 1915, 10 pp., 2 figs. 



The formula for Bordeaux mixture selected as a type is the one 

 most generally met with, and contains copper sulphate 4 lb., quicklime 

 4 lb., water 50 U.S. gals. (41-J Impl.) ; this is usually known as the 

 4-4-50 mixture. The effect of the method of mixing in producing 

 a greater or less volume of precipitate is pointed out and the adoption 

 of a method which gives the most slowly settling mixture is 

 recommended. An ideal Bordeaux mixture would be one which, after 

 a given lapse of time, would show no perceptible settling. The relative 

 value of hydrated lime and quicklime is discussed, preference being 

 given to the latter, which produces a finer milk of lime. As hydrated 

 lime is in the form of a powder, there is no way of telling to Avhat 

 extent it has deteriorated by becoming carbonated on exposure 

 to air ; carbonate of lime cannot be used in Bordeaux mixture. 

 Temperature influences the bulkiness of the precipitate very 

 considerably, and a mixture made with water at 50° F. is about twice 

 as valuable as one made with water at 54° F., and three times as 

 valuable as one made with water at 65° F. The temperature of the 

 solution after it has been made has a marked influence on its 

 durability. The time required for a 4-4-50 Bordeaux mixture to 

 deteriorate completely varied from 192 hours at 48° F. to 3 hours at 

 86° F. Cane-sugar, recommended hy Kelhofer, is by far the most 

 efficient preservative, the addition of 2 oz. to 50 U.S. gallons being 

 sufficient to prevent deterioration for a considerable length oT time. 

 The addition of this small amount in threatening weather will permit, 

 should rain ensue, the maintenance of the mixture in good condition 

 until work can be resumed. As an akaline Bordeaux mixture cannot 

 contain any copper in solution, a test for alkalinity is the only one 

 needed. If the mixture is not alkaline, there may be copper in solution. 

 When a 4-4-50 mixture is made with a good quality of quickhme, 

 the test is superfluous. Proprietary Bordeaux mixtures are obtainable 

 either in powder or paste form. Powdered Bordeaux mixture does 

 not change with age ; its value depends on the care exercised in its 



