93 



food-plants varied. In cacao a swarm advanced 100 yards in half an 

 hour ; other swarms under observation advanced three-quarters of a 

 mile in a day. In the Guarama district the swarms seemed to be 

 travelling in a westerly direction. Cof?ee leaves were not touched and 

 guinea grass was only injured to a slight extent. After maize, bananas 

 were the favourite food-plant. Other plants attacked included cacao, 

 Heliconia sp., carat palm, gru-gru palm, castor oil plant, nettle, 

 cassava, etc. The dense tropical growth of the country, with the 

 exception of a few small open savannahs covered with grass, appeared 

 to restrict oviposition. Suitable breeding grounds were small and 

 scattered, resulting in the small isolated swarms found all over the 

 country. No natural enemies of any consequence were observed. 

 The following is a summary of the developmental stages :■ — Adults 

 ovipositing, 1st June ; first appearance of hoppers, 25th June ; first 

 appearance of next generation of adults, 29th August. So far as 

 could be ascertained, a great part of the peninsula forming the north- 

 westerly border of the Gulf of Paria was infested by isolated swarms 

 of hoppers. 



RoRER (J. B.). Report on the Inoculation of LoGUsts with Coccobacillus 

 acridiorum. — Bull. Dept. Agric, Trinidad and Tobago, Port of 

 Spain, xiv, no. 6, 1915, pp. 197-198. 



Inoculation experiments with Coccobacillus acridiorum against 

 ScJtistocerca paranensis (Venezuelan locust) and Tropidacris dux (giant 

 locust) showed that this organism is virulent for both these insects, 

 and that the virulence could be increased by passage through a 

 series of them. Pure cultures were made of the organism for use, 

 should occasion arise. 



^j CoLLENS (A. E.). The Manurial Value of Locusts. — Bull. Dept. Agric, 

 Trinidad and Tobago, Port of Spain, xiv, no. 6, 1915, p. 199. 



Analyses of locusts carried out in Trinidad showed that their bodies 

 are rich in nitrogen. In dry examples of Tropidacris dux a total of 

 96"5 per cent, organic matter contained 11 '30 per cent, nitrogen, and 

 in the case of Schistocerca paranensis 96"45 per cent, organic matter 

 contained 12" 18 per cent, nitrogen. The remaining ash was made 

 up of 1'16 per cent, potash and 1*63 per cent, phosphoric anhydride 

 in T. dux, and of 0"94 per cent, potash and I'ii per cent, phosphoric 

 anhydride in S. paranensis. 



Urich (F. W.). Insects affecting the Coconut Palm in Trinidad. — 



Bull. Dept. Agric, Trinidad and Tobago, Port of Spain, xiv, no. 6, 

 1915, pp. 200-203. 



Various insects attack coconut palms in Trinidad. Rhynchophorus 

 palmarum, L. (gru-gru beetle) is attracted to trees which have been 

 wounded or are suffering from fungoid or bacterial disease. The 

 larvae are preyed upon by the larvae of an Elaterid and a Histerid. 



