SECTION X. — METHODS OF CUNTKol,. 13i> 



present no method, except perhaps spraying, has been suggested for 

 destroying those eggs in the ground. Those in the cane and grass 

 sheaths can be destroyed by the processes of trashing and weeding. 



Trashing (Stripping) : Trashing in Trinidad consists of the removal 



of the dead leaves of the cane by hand from the growing plant, and 



• must not be confused with the process of spreading the trash round the 



young plant in the dry season for which process the word '• trashing " is 



used in Barbados. 



The dead leaves when stripped from the plant are either left in heaps 

 (boucans) between the rows of canes, or i-emoved from the fields and 

 used as bedding for the stock. 



The value of trashing as a control method for destroying froghopper 

 eggs depends on two important facts. First the operation must be 

 performed at the time when the eggs are in the trash, and secondly that 

 the trash must be removed from the fields. 



The first condition necessitates that the trashing should be done 

 shortly after a brood of adults (except in the case of the last brood). 

 A careful watch should be kept, with the use of light traps if possible, 

 for the height of the brood and the trashing should be done about ten 

 days later. It is probably the neglect of this fact or that has 

 produced the contradictory results so far obtained. A delay of little 

 more than a week may allow the hatching of the eggs and only the 

 empty shells are then removed. 



If the trash is left in rows or small heaps among the canes little or 

 no result is obtained, as these rows produce almost ideal conditions for 

 the hatching of the eggs and the development of the young nymphs. The 

 trash must either be placed in large heaps at the edge of the field, or 

 be removed to the stock pens as bedding. 



The eggs that remain in the trash during the dry season can b& 

 removed in the same way by collecting the trash from the fields after 

 the cane is cut and piling into large stacks for removal to the pens later 

 as required for bedding. This is already done on one or two estates in 

 Trinidad and. though expensive, is worthy of extended trial, particularly 

 in fields liable to froghopper attack. 



The question was raised as to whether eggs removed in the trash in 

 this way could survive while the trash was in the pens and be returned 

 to the fields with the pen manure, which would thus be a source 

 of danger. 



Experiments have shown that this can not happen. Trash con- 

 taining some hundreds of eggs was buried among the bedding in a cattle 

 pen on Cedar Hill Estate and two months later was removed. None of 

 the eggs subsequently hatched when kept in suitable conditions. The 

 temperature in the manure heap in the vicinity of the eggs was over 

 125'' F. (51° C.) and it is almost certain that none could survive such 

 a temperature. 



Occasionally fields are reported to have been severely damaged 

 shortly after trashing. The probable explanation is that the trashing 

 has been done too severely, that the damage is due to the previous 

 brood of adults which naturally is not influenced by this process, or that 

 it has been done during a spell of dry weather when the canes are 

 suffering from a want of moisture and are sending out adventitious roots 

 beneath the trash, in the attempt to get more water. The sudden 

 exposure of these roots to the direct heat and dryness of the day has an 

 injurious effect on the canes. 



Weeding. Much the same remarks apply to weeding as to trashing 

 and the contradictory results obtained by different planters are probably- 

 due to similar reasons. 



