224 
UEPORT ON KCONOiriO UNTOMOLOCiY 
Forage pest 
would probably be the more suitable for this purpose, as there is a danger of stock suffering 
from hydrocyanic acid poisoning if green immature ilura is used as forage. 
Lastly, children might be employed to collect the borers while the crop is still young 
Infested plants are easily detected by the central growing shoot wilting and turning brown. 
It is, perhaps, hardly necessary to point out that to be effective these measures must 
be carried out by all the farmers in a district. It would be of very little use for a man to 
burn his stubble and plant trap crops if his neighbours on either side allowed the borers 
to breed with impunity. 
The White Nile .\k5iy Worm 
Uemt'tjia fi-Hgalis, Fab. 
Plate XXVIl., figs. 7, 9, 10 
The larva of Itrinegia fnigalix has been given the above local name owing to the 
belief among the natives that it is brought liy the rising White Nile. 
Two outbreaks of this pest occurred in 190(5—on the Government Forage Farm at 
Khartoum and on the Cavalry Forage Farm at Shendi. In the latter place an area of ten 
feddans (acres) of garowi grass {Aiiilrnpagon halepensin) was reported to have been stripped 
in a single night. 
It was only noticed feeding on garowi and dura, but probably it would not hesitate to 
attack wheat, barley and other cereals. 
Larva (tig. 7). — A yellowishdirown to dark brown caterpillar, varying from 40 mm. 
to 55 mm. in length. 
Head, light brown, with a paler median strijie. Body with two dark stripes on the 
dorsal surface, leaving a pale median dorsal stripe. Spiracles dark. yellow sub-spiracular 
line, and a median ventral longitudinal dark brown line. On the seventh and usually on 
the eighth segments are two black longitudinal marks, situated on the outer edge of the 
sub-dorsal stripes. At the junctions of the fourth and fifth and of the fifth and sixth 
segments, on the dorsal surface, are black transverse marks bearing small white spots. 
These marks are very conspicuous when the larva rests with its body curved, but are 
frequently invisible when the body is straight. 
The prolegs are situated on the eighth, ninth and anal segments. 
Both light and dark forms of the larvte occur. 
Pupa .—Dark brown, covered with a purplish bloom and 18-19 mm. in length. 
Adult (figs. 9, 10).—A brown moth, about 17 mm. in length, and with a wing expanse 
of 40-45 mm. 
On the fore-wing is a slanting transverse dark line, between which and the margin 
is a row of seven or eight dark S250ts. 
Ilind-wing similar to the fore-wing, but the markings fainter and the row of sjiots 
re].)laeed Iiy a dusky shaded line. Sometimes there is a reniform mark on the median area 
of the fore-wing. 
The male differs from the female in having the hind-legs densely feathered and in 
having situated at the base of the fore-leg a tuft of long hair. This is unnotieeable until 
the fore-leg is extended, when it sjirings out on either side. 
When the moth is at rest the wings are laid Hat, forming a triangle. 
Life-hisforii and hahifs .—The larvie were first observed when about half-grown, feeding 
on the foliage of dura. The leaves were stripped to the mid-rib, but, as the larvae 
commenced with the lower leaves, it was not until a considerable amount of damage had 
been done that the attack became very noticeable. 
