KEl’OKT ON ECONOMIC ENTOMOLOGY 
233 
Preventions and remedies . — -The infested melons should bo collected and burnt. On no 
account should they be thrown into the river, as a large proportion of them would float 
down stream and be a source of infection to other cultivations. 
The Melon Stem Borer 
During March of this year Mr. Hewison, of the Agricultural and Lands Department, 
called my attention to some grubs that were tunnelling in the stems of sweet melons growing 
on the Government Experimental Farm at Halfaya. Five specimens were brought to the 
laboratories, but at the time of writing only one has reached the adult stage. They proved 
to be the larv® of a longicorn beetle. 
This pest has also been recorded from Eufaa on the Blue Nile. 
Larva.—\ yellow transversely-wrinkled footless grub with a brown head and a few short 
hairs scattered over the body. Thoracic shield white, anteriorly marked with brown. 
Length, about 15 mm. 
Adult .—Dark brown, densely clothed with pubescence yellowish-brown in colour with 
the exception of two broad transverse white bars on the elytra. 
Length, 9-125 mm. 
Life-history .— The larva tunnels in the stem just above the ground level. The single 
specimen bred out under observation pupated without forming a cocoon, lying naked on the 
surface of the soil. The adult emerged in six days. 
The Melon Fruit Fly 
Dacus, sp. 
This pest, which appears to attack melons wherever they are grown in the Sudan, 
was described and figured in the Second Report, Wellcome Research Laboratories. It is 
responsible for a considerable loss to cultivators in the course of the year. 
The adult is a pretty fly 7-10 mm. in length, and with a wing expanse of 12 14 nmi. 
It is wasp-like in appearance and in colour ashy-grey to In-own with yellow markings. 
It may frequently be seen sunning itself on the melon loaves, but, being shy in habits, 
would hardly be noticed unless looked for. 
The larva is 10-12 mm. in length and creamy white in colour. It is a typical 
“ maggot ” in shape, being bluntly truncated posteriorly, and tapering to a point at the 
head end. 
The puparium is of the same colour as the larva and 6- 7 mm. in length. 
Life-history and habits . — With her sharp ovipositor the female fly places her eggs beneath 
the rind of the developing melon or cucumber. The larv®, on hatching, tunnel about in the 
fruit, causing rapid decomposition to take place. 
When cucumbers are attacked the larvte first work up the centre, among the seeds, 
before tunnelling in the walls of the fruit. 
When mature they leave the melon or cucumber and pupate just below the surface 
of the soil. 
The adults emerge in from nine to ten days. 
Where food plants are available this pest breeds continuously throughout the year. 
Food plauts.— V\\e melon fruit fly will attack water melons {hatikh), sweet melons 
{shammam), cucumbers (khiar), and probably many other members of the same family. 
Preventions and remedies . — The custom in vogue at jiresent is to leave the infested melons 
to rot on the ground, thus giving the larva) every chance of completing their life-cycle. This 
