26 



the more destructive and is found only in sandy soils ; R. suhiitida 

 occurs in small numbers in allu^^al soils, and is sometimes very in- 

 jurious in red hill-soils. E. vestita deposits from 20 to 30 eggs singly 

 in June and July at a depth of 15 to 20 inches and the grubs emerge in 

 28 to 34 days and begin feeding on humus and lirmg vegetable matter, 

 being most destructive from January to March. When full-grovm 

 they pupate in April or May in earthen cells at a depth of 6 to 18 

 inches, the adults emerging after 31 days and remaining on the ground 

 for another week or two. Sugar-cane of all ages is attacked ; fields 

 replanted from January to March suffer severely. Enemies of these 

 grubs are a wireworm, Monocrepidius pallipes, Esch., and a Scoliid 

 parasite, Discolia ovalanensis, Sauss. ]\lites attack the grubs in con- 

 siderable numbers in capti\ity, but apparently do not exercise much 

 control in the field. Cane should not be planted in infested fields until 

 April ; it will then be free from serious infestation until December or 

 January, when it "u-ill be well established and better able to resist 

 attack. Beetles and grubs should be collected by hand when possible, 

 and the frequent ploughing of infested fields will expose many of the 

 grubs to destruction by niinah birds. R. subnitidm is very similar 

 in life-history, seasonal occurrence and habits. As the reproductive 

 powers of both species are similar, the relative scarcity of R. subiiitidus 

 is worthy of further investigation ; it is probably due to some enemy 

 peculiar to this species that has escaped attention, or to some factor 

 in the soils frequented by the grub. The remedial measures for both 

 are similar. 



Adoretus versutus, Har. (rose beetle) is not generally regarded as a 

 pest of sngar-cane, but has been found attacking the germinating eyes 

 of recently planted canes. The grubs occur in all types of soil, usually 

 within G inches of the surface, and the beetles are found throughout 

 the year. Only slight damage is done to sugar-cane. 



Scolia manilae. Ashm., the parasite introduced to control white 

 grubs in Hawaii with so much success, has been imported into Fiji and 

 liberated. While the success of this experiment cannot yet be deter- 

 mined, grubs of R. vestita and A. versutus have undoubtedly been 

 attacked by the parasite and adults were subsequently reared. 



Wireworms occurring in Fiji cane-fields include Simodactylus cin- 

 namomeus, Boisd., Zflco>i strict icollis, Fairm. and Mo)iocrepidius poUipes, 

 Esch. The first two species are very destructive to young cane, while 

 the third is beneficial, as it is a formidable enemy of R. vestita. 

 S. cinnamo7n€Us is by far the most abundant species, being found in 

 all types of soU, but reaching its maximum numbers in rich low-lying 

 flats. Its life-history and habits have been described [R.A.E., A, v, 

 182]. While this beetle is very difiicult to control, beneficial results 

 have been obtained by continuous planting of a certain proportion of 

 the rows, transplanting being done only in wet weather. Cane on 

 allu\'ial flats should be second ratooned, as by this means the annual 

 planting area is reduced ; drainage should be improved wherever 

 possible and the importance of clean cultivation cannot be over- 

 estimated. L. striciicoUis is neither so abundant nor so voracious ; 

 its feeding habits are similar and remedial measures identical. 

 M. paJlipes ^ found only in sandy soils, and has never been known 

 to attack cane. 



