187 
Joint, a portion of a cane stem from node to node. Enor- 
mous number of variations in one or other of its parts—leaf- 
scar, bud, root-zone, growth-ring, bloom-band. Select leaf- 
scar and bud for more detailed study. 
Leaf-scar: its orientation, horizontal or descending; mode 
of embracing stem; circlet of hairs; scar-band, scar-line, etc. 
Bud: epitome of vegetative shoot; shooting, bursting, size 
and shape; point of origin; flanges; vestiture, etc. 
The founding of a natural system on these and other char- 
acters too numerous to mention. An analytical key not aimed 
at, but a system founded on natural affinities. The magnitude 
of the task without the aid of floral characters. Four natural 
groups at present evolved: Chin, Rheora, Pansahi, Nargori. 
A summary of the characters of three of these groups. 
The general primitiveness of Indian canes and the similarity 
of the Chin group to Saccharum spontaneum. 
THE INSECT PESTS OF SUGAR CANE AND THEIR CONTROL 
IN BRITISH GUIANA. 
By G. E. Bopxty, B.A., Dip. Agric. (Cantab.), F.Z.S., F.E.S., 
Government Economic Biologist, British Guiana. 
[ ABSTRACT. | 
Insect pests of sugar cane have been known in British 
Guiana for at least the last quarter of a century, but it is only 
during more recent years that they have received any serious 
attention and combined efforts have been made for their control. 
The most injurious pests are those known collectively as 
‘““ Borers,’’ which consist of three distinct species of lepido- 
pterous larve, namely, a member of the Castniiadae (Castnia 
licus, Fab.) and two species of Pyralidae (Diatraea saccharalis, 
Fab. and Diatraea canella, Hps.). Other important pests con- 
sist of Termites popularly known as White Ants, of which 
there are two species, Eutermes costaricensis, Holmgr. and 
Mirotermes nigritus, Silv.; the larve of the Noctuid Moths, 
Laphygma frugiperda and Remigia repanda; the Mealy Bug, 
Ripersia sp.; and the Weevil Borer, Metamasius hemipterus, 
Linn. 
A number of these pests are attacked by several kinds of 
hymenopterous parasites, especially the Small Moth Borer, D. 
saccharalis, whose eggs are infested by the well-known Tricho- 
gramma minutum, Riley. 
