AN INVASION OF BRITISH GUIANA BY LOCUSTS. 355 



a little practice the discovery of spots where eggs had been deposited became an easyf 

 matter, and it was only necessary to fork up the soil to the depth of a few inches 

 so as to secure the masses. 



Burning. 



This proved a particularly successful procedure on the coastland areas, where 

 the atmospherical conditions are drier than those within the forest area. Thus on 

 the Essequebo Coast at Onderneeming, and other centres, the greater number 

 of the young hoppers were destroyed within a week of their appearance by this means. 

 The usual method on locating a swarm in low bush was to collect a large quantity 

 of dry bush, roughly surround the insects, and put fire all round simultaneously. 



A modification of this method, when the hoppers were found in cultivations, 

 was to drive the swarm slowly towards a pile of dry bush roughly arranged in the 

 form of a semicircle ; as soon as the young hoppers arrived within this area the bush 

 was promptly lighted all round and, fresh bush being placed behind the swarm, 

 they were thus totally surrounded and destroyed. A swarm in high bush were 

 killed by chopping away the surrounding growth thus isolating the infested area. 

 Dry bush was then piled around and set on fire. 



Early in the morning and also towards eventide the hoppers clustered together 

 in dense masses. This habit gave the burning method full scope. 



This manner of elimination proved efficacious till the hoppers were half-grown, 

 after that their improved powers of locomotion made it possible for them to leap 

 through the flames and escape. Also at this period of growth and later the insects 

 became more restless in their movements and the slightest disturbance or the 

 appearance of human beings caused the whole swarm to scatter in a general " sauve 

 qui peut." They also became wary and the faintest suspicion of smoke from 

 burning vegetation caused them to make off. These acquired characteristics eventu- 

 ally rendered attempts to destroy them by burning a profitless method. 



In the forest areas, such as the North West District and some parts of the 

 Pomeroon and Monica Eivers, dampness caused by heavy rainfalls and dew rendered 

 the burning method less easy than elsewhere, but in these areas the presence of 

 numerous small drainage trenches created an excellent alternative. 



Driving into Trenches. 



This proved an easy and efficacious method. When a swarm had been located, 

 it was slowly driven by a number of people towards a drainage trench, and as 

 soon as it reached the water kerosene oil was poured in, which instantly formed 

 a film on the surface. This film of oil rapidly killed the hoppers as soon as they 

 came in contact with it. Here again, when the hoppers became about three-parts 

 grown their increased strength often enabled them to make their way across 

 the trench and escape. A futher objection to this method was that driving could 

 only be effectively performed when the vegetation was scant. Thick grass or bush 

 allowed the hoppers to secrete themselves among the roots, and it was observed 

 that they soon became highly skilful at effacing themselves in this manner. 



