192 



would appear that the adults of the second generation preferably 

 oviposited on the grapes of the most exposed portion of this trellis. 

 This vineyard was also severely attacked by mildew and brown rot. 

 Vineyards treated with golazine or with arsenic showed no advantage 

 over untreated ones used as controls. Tables are given to show the 

 amount of damage that may be caused by this moth, and the habits 

 of the larva and the way in w^hich it destroys the grapes are described. 

 It is pointed out that none of the insecticides at present in use agamst 

 it appear to give very satisfactory results. 



\ Sekre (P.). L'lle de la Trinity menac6e d'une invasion de Sauturelles. 



"^ [The Island of Trinidad threatened by an Invasion of Locusts.] — 



Bull. Mils. National Hist. Nat., Paris, no. 2, 1916, pp. 101-104. 

 [Eeceived 16th March 1917.] 



A description is given of the threatened invasion of Trinidad in 

 1915 by locusts from Venezuela, where they had caused considerable 

 damage [see this Review, Ser. A, iv, pp. 92, 170]. 



The best control measures recommended are the spraying of plants 

 with arsenical compounds composed of 4 lb. of paste arsenate of lead 

 to 50 gals, of water and 4 lb. of quick lime ; or 1 lb. of white arsenic 

 / and 4 lb. of carbonate of soda dissolved in 1 gal. of boiling water 

 added to 50 gals, of water containing 3 lb. of quick lime and 1 

 gal. molasses; or the more practical method of spreading poisoned 

 bait containing white arsenic or the arsenates of soda or lead. This 

 bait is made by mixing 2|- lb. of white arsenic, 50 lb. of sawdust, 

 6 chopped, bitter oranges or lemons, 4 lb. of molasses and 5 gals, 

 of water. Sufficient water is then added to render the whole of a 

 convenient consistency. 



\^ It is also suggested that an attempt should be made to infect with 

 Coccobacilliis acridiontm the locusts all along the shores of the Gulf 

 of Paria, so as to form a barrage in which those coming from the 

 interior of Venezula would become infected and thus prevented from 

 reaching Trinidad. In order to be effective, the campaign should be 

 carried out throughout all the districts of Venezuela invaded by 

 Schistocerca americana and continued for two or three years. 



Only two species of non-migratory locusts are found in Trinidad ; 

 S. praesignata and the giant locust, Tropidacris dux, which is not 

 prolific and has many natural enemies. Experiments made on the 

 last species with Coccobacillus acridiorum showed that the virus 

 killed after 36 hours at the first passage and in 18 hours at the second. 

 At the height of its virulence it caused death in 4-6 hours. 



P. L. Un Congres centre les Sauterelles. [A Congress against 

 Locusts.]— i?ev. de Vitic. Paris, xlvi, no. 1182, 22nd February 

 1917, p. 123. 



It has been decided by the International Institute of Agriculture, 

 on the suggestion of the Agricultural Service of Morocco, to call an 

 international conference to discuss methods of controlling locusts. 



South Africa and South America have adopted international regu- 

 lations for combating the primary foci of locusts, and it is to be hoped 

 that the initiative taken by the Morocco Protectorate will lead to a 

 mutual understanding in the northern hemisphere. 



