and stocked as aforesaid, at the time the much younger cane of 

 the rest of the field began to l)e infested with hoppers, would 

 daily be distributing thousands of natural enemies, that should 

 control these. Although such a plan or modification of it might 

 be adopted on some plantations, on others (at least such as are 

 under irrigation) it would either be difficult, or altogether im- 

 practicable. ( )nly in the case of some fields of long ratoons 

 would the matter be very simi^le, when a small area of the 

 original ratoon growth in each field could be left uncut, and if 

 well supplied with hoppers and their natural enemies would 

 serve later on to stock the rest of the field. Unfortunately, 

 owing to the fact that ratoons are (except in unusual cases) not 

 severely attacked as compared with plant-cane, this matter be- 

 comes one of minor importance. Otherwise, in the majority of 

 cases, owing to the clearing of large areas and the burning of 

 trash, it is probable that new fields will have to be supplied by 

 cages similar to those already used. Two things will be abso- 

 lutely necessary : ( i ) that the new fields be well supplied with 

 ])arasites ; (2) tliat they be stocked immediately the hoppers en- 

 ter them and conimence laying. 'This plan, though less satis- 

 factory than would be the other method, is nevertheless simple, 

 and does not call for much expenditure of time, nor for skilled 

 labour. The one thing necessary to be' positively ascertained is 

 that the spot whence the cuttings for distribution are taken is 

 well supplied with all the kinds of parasites that it is desired to 

 establish in new fields. It is now well known to us that (/// these 

 destro\ers are not \et estal)lished /// (/// parts of all plantations, 

 and therefore at i)resent unless an entomologist jireviously 

 test samples from the spot, whence distribution is to be 

 made, it is cjuite likely that some of the most valuable parasites 

 will not be taken to the new fields. If a sample be submitted 

 to the entomologists, it can be ])assed as fit to supply all neces- 

 sary parasites to new fields, or if not, cages of the deficient 

 species can always be supplied from the cane in the grounds of 

 the Experiment Station in Honolulu. As the parasites are con- 

 tinually spreading and increasing, such expert examination will 

 at the most be necessary for a year or two; for it is perfectly 

 certain that by that time all the species will be so general that 

 it will be c|uite impossible to take anv extensive sample of cane- 

 leaven that bear eggs of leaf-hopper, which will not contain all. 

 Such in fact is now the case in the cane at the Experiment Sta- 

 tion. To sum up, the clearing of all canj? from large acreages 

 is a decided obstacle to the complete success of natural enemies 



