12 



per are not always followed by a very large fungus growth, for 

 apparently much depends on climatic conditions. Very heavy 

 rains sometimes so entirely wash off the hoiieydew that no me- 

 dium for fungus growth remains. These fungi necessarily add 

 to the damage done by the leaf hoppers. Though they send no* 

 hyphae into the tissues of the leaf, yet they sometimes entirely 

 cover these, and the white fungus may be stripped off from either 

 surface in flakes of considerable thickness, forming a solid shield 

 against light and air. 



The result of leaf-hopper attack when very severe is seen in 

 ihe drying up of the leaves (from the constant sucking of their 

 juices) before their full functions are performed. In consequence 

 of this the joints of the stem, even at the time when they should 

 be thickening, become on the contrary tapering and contracted, so 

 much so sometimes that the crown topples over and is even en- 

 tirely destroyed, further growth, of course, being at an end. 

 Young cane is sometimes entirely killed out before any consid- 

 erable length of stem has been produced. 



Although total destruction of a plant only occurs when the leaf- 

 hopper is in the most excessive numbers, yet even when present 

 in large num1)ers the injury done must be considerable. Should 

 a plantation, thus attacked, after all produce a crop that comes up 

 to the estimates, yet it is safe to say that without the pest these 

 would be largely exceeded. 



REL.\TIVE IMiVIUNITY OF DIFFERENT VARIETIES OF CANE FROM 

 ATTACK. 



7. Some varieties of cane, other things being equal, appear 

 less subject to attack than others. It must not be for a minute 



*0f course reference is here made only to the fungi whicli usually fol- 

 low the attacks of Homoptera. Several species of true leaf parasites .ire 

 found in the cane-fields and appear now to be more than usually dis- 

 seminated, possibly owing to the abundance of leaf-hoppers and insects 

 accompanying them, that carry the spores. These fungi so far as I have 

 examined them appear all to be known in other countries and are prob- 

 ably importations into Hawaii. 



