om 
602 i THE WHITE COFFEE-LEAF MINER. 
more difficult to choose a proper remedy for a disease with which 
he is familiar, than to trace out the nature and progress of the 
disease. But at this day the science of entomology, particularly 
in its practical application, is of such recent origin, that it suffers 
under a disadvantage from which the practice of medicine is free, 
namely, it possesses no treasury of results drawn from experience. 
The practical entomologist can only recommend measures to be 
put to the trial, and in this way gradually gather a body of experi- 
mental facts which may serve as a guide in the future. a 
i 
3 
The most obvious remedy which suggests itself is the collection 
and destruction of the leaves which contain the living larvæ. 
If this was done thoroughly, it would no doubt result in the 
complete extermination of the pests, a result the value of which 
would be incredible. J 
Towards this end Guérin recommends (Mém., etc., pp- 18-20) 4 
that “the branches of the coffee-trees which are loaded with : 
[infested] leaves should be ‘cut off in all parts of the country “ i 
one time, and burned, while the insect is in the larva state. 
If this were done, he says, “ these coffee-trees should be cut down : 
in such manner that the vegetation could resume its ordinary COE 
shortly after the operation, to the end, if it were possible, of not : 
having to regret but one crop of coffee. * * To attain this condi- 
tion more promptly, the operation in question should be = 
with a cutting instrument, and at a height which should be et . 
mined by the proprietor himself (a metre and a half). Care shoul 
be taken to preserve here and there some young and vigorous 
branches, which would tend to maintain the equilibrium of the oF 
in all parts of the plant. * * Afterwards the development of eu! st 
leaves ought to be watched with the greatest exactness, and F 
there should appear from place to place some spotted leaves, ax! : 
should be destroyed promptly.” : 
It will be seen that Guérin expects to cause 
crop of coffee in his endeavor to exterminate t Hee i 
tainly the issue of the experiment, if successful, would a a oo 
worth the loss of an entire crop, but I think the same Bene 
be obtained in a preferable way: entailing much more la oe 
avoiding at the same time the loss. Probably not a e 
would be free from infested leaves, so that it would be , es! of 
to find some other means of killing the larve in theher 
those branches which remained. On the other hand, many ™ 
; 
the loss of one 
he insect. VO 
