218 
REPOKT ON ECONOMIC! ENTOMOLOGY 
Filth-feeding' 
Hies in 
Khartoum 
around its hind margin a series of flesliy spines ; the stigmatic plates on this segment, 
too, are extremely small and wide apart (2 mm. apart in an adult larva), while in the 
Tumbn fly maggot they are much larger and close together (at the nearest point separated 
by less than the diameter of a single stigmatic plate).” 
The Tuinhu Fly occurs throughout the greater part of Tropical Africa, being recorded 
froin tlie West Cloast, Congo State, Rhodesia, Natal and other places. 
It is not definitely known in what way the host becomes infested or whether the 
female produces eggs or junmg larvie. The larva lives in a cavity that it forms under 
the skin of Imman Ijeings and other animals, where it causes intense irritation, and, as it 
develops, considerable pain. This cavity is always connected with the outside air by a 
small oijening, by means of which the larva is enabled to breathe. When mature, the 
larva leaves its host, buries itself in the soil and pupates. The adult emerges in about 
sixteen days. 
TifE Congo F’nooii M.vggot 
Aticlniirraiiiijia Inteola, Falu'icius 
The adult female of Aiichnieroiiii/iu luteahi was figured and a description of its larva 
and an account of its habits given in the Second Report of these Laboratories.' 
Specimens of this fly have been received from the Bahr-El-Ghazal, and it was also 
taken last year in the vicinity of Nasser, on the Sobat. 
The Floor Maggot does not cause true myiasis, hut owing to its resemblance to the 
preceding species it has been thought better to include it under the same heading. 
IV. Insects in.jukious by me.vns other th.\n by Blood-sucking 
l’’lLTH-FEEDINO FlIES 
(u) Family, Mnsciihe 
A small series of observations on the breeding places and habits of the various species 
of filth-feeding flies that occur in Khartoum were carried out early in this year, and the 
results are of interest in that they coincide with those obtained by Smith- at Benares, 
India. 
It is generally supposed that in tropical countries, human ordure, when deposited in 
places to which the sun has access, dries up so rapidly that flies are unable to breed in it. 
Smith found, however, that on the deposit becoming dry the larval burrowed down into the 
soil to a depth of from five to six inches and there pupated, eventually emerging as adults. 
In this case the species was Mnacu (‘uticniata. 
In Khartoum the same conditions prevail. Human ordure deposited in the open, 
although by the second day apparently dry, is yet sufliciently moist in the interior for 
maggots to be able to feed on it. As soon as it becomes thoroughly dry the maggots 
descend into the soil to varying depths, and, in the course of a few days, give rise to adults. 
A small fragment of human ordure, two days old, containing maggots about half-grown, was 
placed on sand in a large open glass vessel and exposed to the sun. By the following day 
the ordure was perfectly dry and the maggots had gone down into the sand, and, notwith¬ 
standing the intense heat to which they were exposed, they completed their life-cycle. 
The sanitary regulations in Khartoum prevent filth-feeding Hies becoming such a 
pest as they are iu the native villages, where they frequently exist in almost incredilde 
^ Wellcome Researcli Lahoratories, Sccoud Reiwrt, 190G, pp. 85-87. 
- Journal of the lloijaJ Army Medical Curjm, August, 1907, p. 150. 
