504 



Pea and Bean Weevils. — Agric. News, Barbados, xiv, no. 340, 8th May 

 1915, p. 154, 1 fig. 



Peas and beans are subject to the attack of beetles of the genus 

 Bruclms. The eggs are laid in the flower or on the very young pod. 

 The larva on hatching, bores into the young seed, rendering it unfit 

 for food or planting. The remedy is to plant only seed which is free 

 from beetles, and to destroy insects in stored seed, which may be 

 fumigated with carbon bisulphide. The Hesperid, Eiidamus proteus, 

 the bean leaf-roller, and theNoctuid, Ayiticarsia {Thermesia)gemmatalis, 

 can be controlled by the application of dry lead arsenate, either alone 

 or mixed with lime. Paris green cannot be used on account of its 

 destructive effect on the leaves. 



H. A. B. Cassava Stem Borer. — Agric. News,' Barbados, xiv, no. 340, 

 8th May 1915, p. 155, 2 figs. 



A species of Cryptorhynchis has been reported on cassava, causing 

 considerable injury to the stem. The borer is little known, so that 

 there has been no opportunity of testing methods for its control. It is 

 suggested that material for planting should be quite free from 

 infestation, and all waste material from infested fields should be 

 burned or deeply buried to kill the larvae or adult weevils. 



Richards (P. B.). A Note on Sulphur- Arsenic Mixtures for fumigating 



Termes gestroi. — Agric. Bidl. Fed. Malay States, Kuala Lumpur, 

 iii, nos. 6-7, March-April 1915, pp. 225-229. 



The method of treating termites with sulphur-arsenic fumes has 

 recently fallen into disuse. Lack of success with the fumigator may' 

 be attributed to insufficient organisation, badly kept apparatus and 

 incorrect methods of preparation of the arsenic and sulphur mixture. 

 The underlying principle of the " Universal " Exterminator, a 

 compound no longer procurable, is the formation of arsenious sulphide 

 from a strongly heated mixture of sulphur and white arsenic. The 

 sulphide is prepared by placing a quantity of the mixture on a charcoal 

 fire in a retort, the heat being maintained under a forced draught from 

 a pump which serves also to drive the fumes out through a nozzle. 

 The latter is inserted into the nest and the fumes are forced in for from 

 5 to 15 minutes. By this means, a quantity of white arsenic is volatilised 

 and driven into the nest ; sulphur dioxide, carbon bisulphide, realgar 

 (As 83), carbon monoxide and carbon dioxide may also be present. 

 The length of the ramifications of the nest prevent complete asphyxia- 

 tion of the ants by these gases. The arsenic is required to poison 

 individuals which escape suffocation and to cover the fungus gardens 

 from which the young are fed, the bodies of suffocated insects and the 

 walls of the nest with a poisonous layer. The dead insects are eaten, 

 and thus more individuals are killed, while the food supply of the 

 young is poisoned. It is important to maintain a high- pressure 

 throughout the operation. The mixture should consist of 87 "5 per cent, 

 by weight of arsenious oxide and 12^5 per cent, of sulphur. The latter 

 should be in the form of flowers of sulphur or finely ground sulphur, 

 and the mixture should be as intimate as possible. 



