20 



wards the tip. After a time the filaments or hyphae of the fungus 

 grow out from the inside of the insect on the ventral surface and 

 attach it to the leaf. Finally special hyphal outgrowths on which 

 the spores are produced, are formed over the rest of the surface. 

 Even after death during the early stages of fungus growth, the hop- 

 pers appear perfectly natural, and without close examination it is 

 not always possible to be sure whether the insect is really dead or 

 merely resting on the leaf. At present we cannot judge of the 

 effectiveness of these fungus diseases, because there has been no 

 special investigation as to their prevalence, and the percentage of 

 leaf-hoppers killed, at the various seasons of the year. As has 

 been mentioned, at the time I looked intO' the matter, the condi- 

 tions were, in my opinion, unfavorable for the spread of such dis- 

 eases, owing to the climatic conditions. It may be said, however, 

 that in Olaa, and no doubt in some few cane-growing districts be- 

 sides, conditions are as a rule cxceptioiially favorable for the growth 

 of entomophthorous fungi, as is evidenced by the large mor- 

 tality amongst insects of all kinds from such parasites. Caterpil- 

 lars, moths, beetles, cockroaches, may be easily found killed by 

 theiu, and the variety of the destroyers themselves is consideralile. 

 Since, however, in most localities, even in the wet mountains, such 

 attacks are comparatively rare or rarely noticed, it is hardly prob- 

 able that these fungi which destroy the leaf-hoppers could be estab- 

 lished in the localities, still less favorable for fungus growth, that 

 are occupied by most cane-fields. 



INSECTS rRESr':NT TN THE AFFECTED CANE FIELDS THAT INCREASE 

 THE INJURY DONE RY LEAF-TIOI'PER, AND BUT FOR THE PRES- 

 ENCE OF THE LATTER WOULD I!E EITHER AliSENT OR FAR LFSS 

 NUMEROUS. 



12. It would not be proper to pass entirely unnoticed the 

 large number of insects attracted to the hopper-aifected cane. 

 Though they have no effect on the leaf-hopper itself, some of 

 them do injuriously atfect the cane. Chief amongst these are the 

 species of Hahtoncus (H. fetragoinis and H. iiiuudus) and two 



