The Animal Parasites of Man

by Harold Benjamin Fantham; Max Braun; J. W. W. Stephens; Fred. V. Theobald

[These puparia are often found in masses at the base of trees, in hollows in trees and rocks just buried under vegetal debris. These insects are generally confined to definite tracts known as “fly-belts.” They usually occur in damp, hot places on the borders of rivers and lakes, and never far from water in the case of the palpalis group, although others of the morsitans group may be found a considerable distance from water. They are usually absent on grass plains, but may now and then occur there (Kinghorn, vide Hindles’ “Flies and Disease, Blood-sucking Flies,” 1914, p. 274); cover of trees, shrubs, or thick reeds is essential to them.

[Their range in Africa extends roughly from 18° N. to 31° S.

[Glossina palpalis is the chief carrier of the more prevalent type of sleeping sickness. Two distinct types of parasites can produce this disease, viz., Trypanosoma gambiense, which produces the ordinary sleeping sickness, transmitted by G. palpalis, and Trypanosoma rhodesiense the Rhodesian or Nyasaland sleeping sickness, transmitted by G. morsitans, and possibly identical with T. brucei, the parasite of N’agana. Koch has also shown that G. pallidipes, Austen, and G. fusca, Walker, can be artificially infected with the human trypanosome. It appears probable that Koch used G. brevipalpis, not G. fusca, in his transmission experiments, as at that time fusca included nearly all the large tsetses, but brevipalpis is its Eastern representative.

[A Table of Species (modified after Austen) is appended here:—

I.
Glossina palpalis Group.
1.	Dorsum of abdomen ochraceous buff or buff; thirdand following segments exhibiting sharply defined,dark brown or clove brown, interrupted transverse bands	tachinoides, Westwood.
	Dorsum of abdomen not so marked	2.
2.	Third joint of antennæ pale (cream buff to ochraceousbuff), clothed with long and fine hair, forminga conspicuous fringe on front and hind margins	pallicera, Bigot.
	Third joint of antennæ entirely dark (mouse-grey)except at extreme base on outer side, and withouta conspicuous fringe of long and fine hair	3.
3.	Dorsal surface of abdomen dark sepia brown;median paler area on second segment broad, andmore or less quadrate or irregular in outline;hypopygium of ♂ buff or ochraceous buff	caliginea, Austen.
	Dorsal surface of abdomen blackish-brown; medianpaler area cuneate (i.e., triangular in outline);hypopygium of ♂ grey	palpalis, Rob. Desv.
II.
Glossina morsitans Group.
1.	Hind tarsi entirely dark; small slender species;abdomen bright ochreous or reddish ochreouswith dark lateral markings	austenii, Newstead.
	Hind tarsi not entirely dark; abdomen drab-grey,buff or ochreous buff with conspicuous darkinterrupted transverse bands	2.
2.	Last two joints of front and middle tarsi withsharply defined clove brown or black tips	3.
	Last two joints of front and middle tarsi withoutsharply defined clove brown or black tips (frontand middle tarsi either entirely pale or, at most,two joints of front tarsi faintly brownish atthe tips), and last joint and distal half of penultimatejoint of middle tarsi light brown, never sodark as to form a sharp contrast with theremaining joints	pallidipes, Austen.
3.	Third joint of antennæ with a distinct fringe of finehair on front margin; dark brown or clove-brownbands on abdominal segments extending close tohind margins (i.e., pale ground colour, apart fromthe median interspace, confined to a very narrowhind border)	longipalpis, Wiedeman.
	Third joint of antennæ without a distinct fringe offine hair on front margin; dark brown or clove-brownbands on abdominal segments not extendingclose to hind margins	morsitans, Westwood.
III.
Glossina fusca Group.
1.	Third joint of antennæ fringed with fine hair onanterior and posterior margins; fringe on anteriormargin conspicuous under a hand lens magnifying15 diameters (nominal) when head is viewed in profile	2.
	Third joint of antennæ with fringe of fine hair onanterior margin so short as to be scarcely noticeableunder a hand lens magnifying 15 diameters(nominal) when head is viewed in profile (longesthairs in fringe in length not exceeding one-sixthof width of third joint); palpi long and slender	3.
2.	Longest hairs in fringe on front margin of thirdjoint of antennæ, in length equal to from one-fourth to one-third (not exceeding one-third) of width ofthird joint; palpi of moderate length	tabaniformis, Westwood.
	Longest hairs in fringe on front margin of third jointof antennæ in length equal to from one-half tothree-fourths of width of third joint; palpinoticeably long and slender	nigrofusca, Newstead.
3.	Pleuræ drab-grey or isabella-coloured, hind coxæbuff or greyish-buff	fusca, Walker.
	Pleuræ dark grey; hind coxæ mouse-grey	fuscipleuris, Austen.
IV.
Glossina brevipalpis Group.
1.	Dorsum of thorax with four sharply defined brown,more or less oval or elongate spots, arranged ina parallelogram, two in front and two behind the transverse suture; proboscis bulb with a sharplydefined brown or dark brown tip	longipennis, Corti.
	Dorsum of thorax without such spots; proboscisbulb not brown or dark brown at tip	2.
	Wings with upper thickened portion of anteriortransverse vein much darker in colour thanadjacent veins and thus standing out conspicuouslyagainst the rest of the wing	brevipalpis, Newstead.
	Wings with upper, thickened portion of anteriortransverse vein not much darker in colour thanadjacent veins, and thus not standing out conspicuouslyagainst the rest of the wings (wings practically unicolorous)	medicorum, Austen.[424]

Glossina palpalis, Rob. Desv.

Fig. 419.—Glossina palpalis and puparium. (After Brumpt.)

[This is the chief carrier of sleeping sickness in Nature. It is found in places over the whole of West Africa from the mouth of the Senegal River to Angola, and extends eastwards into the Bahr-el-Ghazal. The eastern boundary follows the valley of the Nile and includes the eastern shores of Lakes Victoria and Tanganyika; from the southern end of the lake the boundary tends south-west, approximately following the frontier between North-eastern Rhodesia and the Congo Free State, and passing through the Katanga district of the latter country into Angola (Austen). It may occur up to 3,000 ft.; but, according to Bagshawe, it has not been recorded above 4,000 ft. It feeds on the blood of many animals, including reptiles, amphibia, birds, and even amphibious fishes, as well as all the wild mammals. It seems, however, to possess a decided predilection for man, and undoubtedly thrives better upon mammals and birds than upon cold-blooded animals.