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G. E. BODKIN AND L. D. CLEARE. 



creamy-coloured area, which is characteristic of the species. Schistocerca sp. possesses 

 a somewhat similar area but it is not so large, so well marked or so white. The 

 tegmina too show distinct differences ; in S. pattens the costal area bears a few 

 dark markings, and the other maculations on the tegmina are more numerous 

 and darker in Schistocerca sp. than in S. fattens. 

 The duration of the various stages is as follows : — 



Egg to 1st nymph 



1st to 2nd nymph 



2nd to 3rd nymph 



3rd to 4th nymph 

 4th to 5th nymph 

 5th to 6th nymph 

 6th to adult . . 



2- 3 weeks. 

 8 days. 



7- 8 days. 

 10-13 days. 

 10-13 days. 



9-11 days. 

 14-16 days. 



Control Methods. 



As previously mentioned the destruction of the adult insects by any mechanical 

 means, or by hand, is an exceedingly difficult matter and also expensive. 



In a few instances, in some districts, attempts were made to kill the adults, 

 but these were soon given up. The original swarm from Venezuela caused consider- 

 able damage to certain crops, especially Indian corn and cassava. In accordance 

 with their habits, as soon as they alighted, they started feeding and continued 

 to do so for some weeks, till oviposition was accomplished and the next generation 

 safely established. Death then ensued naturally, owing to general weakness 

 and the frayed condition of their wings which prohibited flight. 



The immense swarm of hoppers which eventually made their appearance in 

 the majority of instances got but little opportunity of doing material damage 

 to the crops, owing to the previously described prompt action by the Government. 

 In a few localities, where they were more or less neglected, large areas were com- 

 pletely defoliated. 



A variety of control methods were recommended by this Division, all of which 

 proved efficacious in dealing with the hoppers. Some of these suggestions were 

 based on methods which had proved successful in other countries and others were 

 evolved locally. Thus the molasses sheet method was so successfully practised 

 by Mr. E. S. Nicholson of Anna Regina, Essequebo, that it came to be widely 

 used in other areas. The tar method, though by no means novel in principle, was 

 modified to suit local conditions by the senior author and Mr. A. A. Abraham, 

 then Agricultural Instructor in the North West District. The trench method, 

 in conjunction with a surface film of kerosene oil, was suggested naturally by the 

 presence of innumerable drainage systems rendered necessary by the flatness of 

 the country in the maritime lands of British Guiana. 



Destruction of Eggs. 



This is a most effective method and, when practised on a large scale, gave 

 excellent results. It was not widely utilized, as at this stage but few of the farmers 

 had began to realize — -or were indifferent to — the gravity of the situation. With 



