10 TRINIDAD AND TOBAGO BULLETIN. [XVIIL 1. 



REPORT TO THE FROGHOjPPER COMMITTEE ON 

 MR. GLASGOW'S SUPPOSED CURE FOR FROG- 

 HOPPERS- 



By C. B. Williams, M.A., F.E.S. 

 Entomologist in Charge of Frogliopper Investigations. 



At the end of October it was announced ia the local papers that 

 Mr. Glasgow, dispenser at Orange Grove Estate, had discovered a cure 

 for the frogliopper pest {Tomaqns saccharina). It was said to be a 

 liquid which was poured around the roots of the cane thereby killing the 

 nymphs, destroying the eggs, and also the fungus causing root disease 

 and in addition hai'mful bacteria which the froghopper was believed 

 to deposit. 



Mr. Glasgow was willing to give demonstrations of his method on 

 any estate. 



During the next few weeks several planters visited Orange Grove to 

 see his experiments there and two demonstrations were given on other 

 estates, one at Caroni and the other at Cedar Hill. 



In view of the interest aroused and of the conflicting statements as 

 to results I visited Orange Grove on November 6, in company with 

 Mr. Moodie and Mr. Cox, and again alone on November 14 and 21. I 

 also visited the treated fields at Caroni, in company with Mr. Glasgow 

 himself on November 21, and the 'treated fields at Cedar Hill on 

 November 20, with Mr. Fabian, and again on December 13. 



METHOD. 



The method consisted as reported, of the application of a liquid 

 of secret composition, round the base of the cane plants. The liquid 

 was said to cost about 6 cents per gallon local prices, and possibly 

 4 cents per gallon wholesale. 



Mr. Glasgow also said that as applied to the fields at Orange Grove 

 by the rough and ready method of pouring on the ground from tobacco- 

 tins, one gallon would treat about 20 stools, but that he expected by 

 means of a spraying machine to be able to treat 30 or more stools with 

 one gallon. With 1,750 stools per acre (the number at Orange Grove 

 where all plants ai'e 5x5 feet) the amount of liquid required should be 

 50-100 gallons per acre, costing $3-ft6. 



As regards cost of labour Mr. Glasgow said that six boys could 

 treat about four acres per day, and that on one occasion between 

 1.30 and 5 p.m. they did a plot of 2^ acres. 



The following other particulars were obtained from Mr. Glasgow (1) the 

 liquid would keep in its diluted state for two years ; (2) it had no irritating 

 effect on the skin '■= and gave off no poisonous fumes ; (3) 1-1 J oz. of the 

 liquid as applied to the field would kill a man if taken internally. 



LABOKATORY EXPERIMENTS. 

 On the 6th November we immersed two nymphs removed from their 

 froth in the liquid as applied to the fields for about two minutes during 

 which time they were prevented from crawling out. After this 



* Later Mr. Glasgow stated that the liquid has a slight irritating eflfect. 



