Palpalis Group Research Articles

Classification of nine species and subspecies of tsetse flies (Diptera: Glossinidae: Glossina Wiedemann) based on molecular genetics and breeding data

Adults from nine taxa of tsetse flies (Glossina) were examined by polyacrylamide electrophoresis, and banding patterns for 12 enzymes were determined and interpreted in terms of allele frequencies. Tetrazolium oxidase and manganese-stimulated malic acid dehydrogenase were monomorphic in each taxon. Arginine phosphokinase, glucose-6-phosphate dehydrogenase, and an esterase from testes were controlled by X-chromosome loci. Seven enzymes (xanthine oxidase, aldehyde oxidase, octanol dehydrogenase, an esterase, an α-glycerophosphate dehydrogenase, malic acid dehydrogenase, and alkaline phosphatase) were controlled by autosomal loci. With the exception of Glossina morsitans submorsitans, members of the morsitans group had higher average heterozygosity per locus than did members of the palpalis group. A phenogram, based on mean genetic identities, placed G. austeni in the palpalis group, rather than in the morsitans group. Electropherograms indicated substantial genetic differences between G. m. submorsitans and other subspecies of G. morsitans sensu lato. A strong postmating barrier prevented hybridization of G. m. submorsitans (originating from Upper Volta) with G. m. morsitans and G. m. centralis. Using the X-chromosome loci ocra and salmon as markers, genetical recombination was not observed in hybrids of G. m. morsitans and G. m. centralis.

Tsetse fly male genital segments

Summary 1.The male genital segments of Glossina morsitans morsitans are described. When the posterior segments are flexed forwards under the abdomen, the distal margins of the superior claspers clip into the transverse grooves of the inferior claspers and the aedeagus is protected by the arthrodial membrane between the superior claspers. 2.Other species of the morsitans group flex the genital segments in a similar way, but in the palpalis group the simple inferior claspers hold both the aedeagus and the superior claspers. In most species of the fusca group, the inferior claspers are used mainly for holding the aedeagus. 3.The relationship between the various types of male genital segments in the commoner species is discussed and the type found in G. fuscipes seems to be the least specialized. 4.The form of the male genital segments in G. brevipalpis shows different evolutionary trends to other species of the fusca group, which seems to be polyphyletic. 5.The relationship between the various types of male ...

Giemsa C-banding within the genus Glossina (Diptera, Glossinidae)

The Giemsa C-banding staining pattern of members of both the palpalis and morsitans groups of tsetse flies are described. Similarities in the staining reaction of the heterochromatic Y and supernumerary chromosomes within species have been observed which suggests a common origin. The presence of useful markers in all species/sub-species should assist in the recognition of species/sub-species hybrids.

Some observations on the recent epidemiology of sleeping sickness in Nyanza Region, Kenya, and its relation to the general epidemiology of Gambian and Rhodesian sleeping sickness in Africa

The history is given of sleeping sickness, of both the Gambian and Rhodesian types, in Nyanza Region, Kenya, leading up to the explosive outbreak, in Alego and the surrounding locations in 1964, of T. rhodesiense infections transmitted by G. fuscipes ( G. palpalis fuscipes). Some account is given of the characteristics of this epidemic, of the conditions that may have contributed to it and of the danger of spread to other parts of Kenya. Since this epidemic is in marked contrast to the normal association of T. gambiense with tsetse of the G. palpalis group, and of T. rhodesiense with the G. morsitans group, the reasons for these associations are considered and it is concluded that the usual combinations are the result of selective factors operating in the different conditions in which the trypanosome strains are transmitted. Laboratory and field evidence is quoted to show that there is no reason why, given suitable conditions, either type of trypanosome should not be transmitted by tsetse of either group. It is suggested that the recorded history of the movement of infected persons, the belief then current that G. morsitans did not transmit sleeping sickness, and the early incidence and localization of cases in Nyasaland and Northern Rhodesia, are consistent with the conclusion that, about 1908, a virulent strain, or strains, of Trypanosoma infective to human beings was imported from the epidemic areas of the Congo to parts of Nyasaland and Northern Rhodesia infested with tsetse of the G. morsitans group, and that this strain, or strains, capable of infecting game animals and being re-transmitted from them, gave rise to what is now known as T. rhodesiense.

The epidemiology and control of human trypanosomiasis in Glossina morsitans fly-belts.

The epidemiology and control of human trypanosomiasis in Glossina morsitans fly-belts.

Observations on Mating Scars in Glossina palpalis (R.-D.)

Attention is again drawn to the presence of mating scars in G. palpalis. They vary in degree and are caused by the superior claspers. The function of the inferior claspers is described and a function for the vermiform appendices is suggested. Flies mated under certain laboratory conditions may fail to develop scars, for reasons given. There are no mating scars in the two other tsetse-flies found in Sierra Leone, viz., G. longipalpis and G. fusca owing to the character of the claspers in those species. For this reason it is likely that the scars are confined to flies of the palpalis group. A suggestion is made concerning the physiology of the production of the scars and attention is called to their bionomic importance. The results of spermatheca dissections of unscarred and scarred females are tabulated. From these it is concluded that the absence of mating scars provides a fairly reliable index of the rate of emergence at any particular time.