386 



and liave liad, tlirongii tlie generosity of this company, which kindly- 

 placed at my disposal steainers and other conveniences, a good oppor- 

 tnnity of looking iuto the diseases of this i)lant. 



The following insects were observed as being injurious to sugarcane: 

 (1) The larva of a Xoctuid, (2) Scarabieid larviB, (.3) wire- worms or Dia- 

 brotica larviie. 



THE NOCTUID LARVA. 



This ranks tirst in injuring or destroying many of the jdants in all 

 parts visited, and seems to be evenly distributed from the Clarence to 

 the Tweed River, being somewhat more numerous in the first locality 

 mentioned. This larva is most nninerouson theouter rows, so much so 

 that in some places, as on the Chirence River,the entire plants were often 

 destroyed, not bearing a single healthy or even living cane, while many 

 fields, especially on the Richmond and Tweed, rarely showed any traces 

 of the insect. 



The abundance of the larvae on the outskirts of the fields and places 

 exposed to the Avinds may be readily explained. The moths which are 

 on the wing at night and nearly always fly against the wind will often 

 settle on the first plants reached, and there deposit their eggs. A 

 second reason may be the usual strong winds during daytime not so 

 readily allowing the minute flying enemies mentioned below to hunt 

 up their hosts on the outer exposed parts of fields. 



The eggs are, without doubt, deposited on the tops of plants and 

 rarely in numbers, (]uite likely behind the young leaves, for very often 

 but a single larva or the work of such could be found upon a ptlant. 

 The moth has a casual resemblance to our Arzama which lays its eggs 

 in clusters intermixed with the hairs of the bushy anal segments of the 

 female. Although 1 have looked, I have never found a trace of such 

 eggs. In this species the last segment is not provided with tufts, and 

 the habits no doubt also differ. As the traces of young larviie always 

 indicated, they enter the tips of plants and work their way downward 

 to the heart,- which they destroy. If not forced to leave on account of 

 decay they will begin irregular tunnels several inches deeper, and, if 

 full grown, pupate in one of them, providing first an opening lightly 

 spun over for the moth to issue. The dry and dead top leaves always 

 .aflbrd a favorable place in which to pupate. If the larvaj are compelled 

 to leave the boring on top they come lower down and begin their destruc- 

 tive work behind the leaves, often girdling the entire plant, and, if the 

 entrance is found, usually on one of the eyes. The tunnels run very 

 irregularly up and down, and sometimes the plant is nearly cut off, and 

 this may be the case as low down as on the ground. It is uncertain 

 where the larvse will again enter a plant after leaving a burrow, but, in 

 the first place, no doubt they look for shelter from their enemies, and 

 perhaps sometimes enter the plant at or below the surface of the ground. 

 Otteii ])lants six feet high Mere found uninjured down to the base and 

 here entirely cut up. Young shoots seem to be eagerly sought and 



