ENTOMOLOGY 233 



The Hawaiian sugar-cane 'borer is able to emerge to the surface 

 from any reasonable depth when planted with seed cane. For this 

 reason great care should be exercised in the selection of cane for 

 planting purposes, since new areas can in this way be readily stocked 

 with the pest. It is not practical to treat successfully cane infested 

 with the borer, since the borer is fully protected within the stalk. 

 Therefore, next in importance to the thorough burning of all trash 

 after harvest is the selection of noninfested seed cane. 



The most effective direct measure employed against the cane 

 borer is the collecting of the adults during the daytime from their 

 hiding place within the lower leaf sheaths. The supply of labor will 

 influence the ability to use this method. The method is more fea- 

 sible where the plantation is so situated that women and children can 

 be employed for the work. Care should be exercised in this work in 

 order that the growing leaves may not be broken down. It is 

 obvious that a larger number of beetles will be collected when the 

 wages are based on the numbers collected, but the results are more 

 satisfactory, as regards breaking down the cane, when the wages of 

 the laborers are fixed at a certain amount per day. In the Fiji Isl- 

 ands a method of baiting the beetles is employed, which consists of 

 splitting cane stalks and placing pieces about the edges of the field 

 and within the rows at certain intervals. 



An important point regarding this split cane is that the females 

 usually infest these pieces heavily with eggs and the young resulting 

 grubs bore into the split stalks and perish as the pieces of cane be- 

 come dry. In dry localities the pieces of split cane should be placed 

 in the irrigation ditches during the day and placed out as a bait in 

 the evening, otherwise they dry out rapidly and cease to attract the 

 beetles. 



The Hawaiian Sugar-Cane Leaf-Roller. During the investiga- 

 tions relating to the leafhopper in 1903 the writer found the Ha- 

 waiian sugar-cane leaf -roller, the caterpillar of a native moth, doing 

 serious damage to cane. On sugar cane the very young larva? feed 

 in the crown of the plant where the young leaves have not yet un- 

 rolled. They are thus protected between the natural rolls of the 

 leaf; later on they roll over the margin of a leaf forming a tube 

 for their retreat. When nearly full grown, they are usually found 

 in tubes towards the tip of the upper leaves. These tubes are easily 

 observed if the ragged leaves where the larva} have fed, are exam- 

 ined. The work of the smaller larvae shows as oval or elongate dead 

 spots on leaves which have unrolled in the growing of the cane after 

 the young larvae have fed upon them. 



When disturbed in its retreat, as by its being torn open, or viol- 

 ently shaken, or jarred, the larva wriggles very lively and drops to 

 the ground for escape. This habit is probably to escape from para- 

 sites, many of which prey upon them. The retreat which it con- 

 structs is undoubtedly for the same purpose, as well as for protection 

 from wasps and birds which prey upon it. The caterpillars are full 

 grown in about three weeks from hatching. They molt five times 

 at intervals of about three to five days, and five to seven days between 



