3 



Comstock (10.) describes the specimens from maize as follows: — 



" When full grown it [the larva] measures nearly, if not quite, an inch in length. It is nearly 

 cylindrical, tapering slightly towards either end, and is furnished upon its back with many brown or 

 blackish spots, six upon each segment, arranged in two transverse rows, four in the front row and two 

 in the hind, the hind two slightly wider apart than the middle two of the front row. Each segment 

 has also a spot on each aide (lateral) and two below (subventral). In the late fall brood — rhe hiber- 

 nating larva; — these spots become obsolete, and they resemble very perfectly the borers found in 

 sugar-cane." 



Of the sugar-cane borers he says : — 



"The full-grown borer is about an inch long, rather slender, nearly cylindrical, and craam-white 

 in colour, with a yellow head and black mouth-parts." 

 Howard, (20.) remarking on these facts, observes: — 



"All the larva> which we had seen from sugar-cane np to the present year were entirely white, 

 with yellow head and thoracic shield, but these were all full-grown individuals ready for hibernation, 

 or which had hibernated. In Prof. Comstock's article (10 ) it is shown that all hibernating larvae 

 found in corn by his correspondent, Dr. Anderson of Abeville County, S.C., were pure white without 

 a trace of brown spots. Therefore the brown spots on the midsummer individuals in corn in South 

 Carolina and Virginia afford no argument for the non-identitjr of the sugar-cane and corn borers. 

 Moreover specimens from sugar-cane from Florida collected in October of the present year show the 

 brown spots and variation in the colour of head and prothoracic shield noticed in corn specimens and 

 are in fact indistinguishable from these. In addition to this, from my observations in Westmoreland 

 County, Va., the past August, it seems probable that the loss of the spots is characteristic of the per- 

 fectly full-grown larva, as at this date the few delayed individuals of the first brood are all white." 



Howard further describes and figures the larva, and writes concerning the variation in the spots, 

 &c. : — " There is considerable variation in the size of these spots, and in some individuals they are com* 

 paratively small, while in others (alcoholic) they are so large as to give the whole larva a brownish 

 effect. There are frequently in the alcholic specimens two subdorsal purplish longitudinal lines, and 

 the head and prothoracic plate vary from bright honey-yellow to brown." 



The larva in spirit which I received from Mr. Van Putten, of Roaring River Estate, is 7 millim. 

 long (evidently immature), yellowish-white without spots, head brown. 



Pupa. 



Comstock (10.) says : — " The pupa is rather slender, three quarters of an inch long, dark brown 

 in colour, and very rough upon the buck when viewed with a lens." Howard (21.) gives an enlarged 

 figure of the pupa. 



Moth. 



The Fabrician description, quoted above, evidently refers to the male Gosse (5.), on the other 

 hand, describes the female, writing : — The Diatrcea sacchari is a small-sized straw-coloured moth, with 

 upper wings of a tint best described as an ochry-drab, varied with darkened lines and margined dots. 

 The under wings are pale yellow." 



Comstock (10.) says : — " The moth is of an ashy gray colour and has a wing expanse of about an 

 inch and a quarter. With the female, the hind wings are nearly of the same colour as the fore, while 

 with the male the former are silvery white." 



Prof. Riley (see Howard, 21.) examined over fifty specimens, and found that "there is great varia- 

 tion both as to the distinctness of the transverse lines and of the terminal series of dots, and as to the 

 general ground colour. It is also noticeable that the later-bred specimens from the South are, on the 

 whole, darker. The males are generally much darker than the females." The moth is figured by 

 Comstock (16.) and by Howard (21.) 



Habits. 



Mr. Howard (21.) sums up the life-history thus : — " In early spring the parent moth lays her eggs 

 upon the leaves of the young cane near the axils and the young borer penetrates the stalk at or near 

 the joint and commences to tunnel, usually upwards, through the soft pith. The larval growth is 

 rapid and the borer is active, and frequently leaves the stalk at one place and enters at another, making 

 several holes in the course of its growth. When ready to transform, it burrows to the surface, making 

 a hole for the exit of the future moth, and transforms to the pupa state. There are several generations 

 in the course of a season and the insects hibernates in the larval state within the stalks." 



Moat of the above is taken from Comstock (10.), who gives the larval period as 30 days* when 

 reared in confinement at Washington, but " in midsummer in the South the growth will probably be 

 much more rapid." The duration of the pupa state in summer, he says, !i is probably not more than 

 six day or eight days." Eggs laid by a moth at Washington hatched in a week. Thus the whole period, 

 from egg to moth, may be taken roughly at six weeks. 



The larval period in the Lesser Antilles is given by Mr. Gr. W. Smith (24.) as about 30 days, but 

 as his account of the habits appears to be derived from that of Comstock (10.), it seems probable that 

 this statement is not founded on direct observation. 



Natural Enemies. 



Very little is known of the natural enemies of the Sugar-cane Borer. Mr. Smith (24.) write 

 that " in some places it has been found that there are ants in the ground which prey upon the bores 

 and help to keep it in check." Prof. Morgan (22.) found the larva of a beetle (Chauliognathus pennsyl- 

 vanicus) in the burrows feeding on the boring larva; in Louisiana. 



* On p. 241 he says 30 days, but on p. 244, 37 days is given as the period. Probably one or other of these tigure 

 is a misprint. 



