Tsetse Flies (Diptera)

Abstract Background Glossina (tsetse flies) biologically transmit trypanosomes that infect both humans and animals. Knowledge of their distribution patterns is a key element to better understand the transmission dynamics of trypanosomosis. Tsetse distribution in Rwanda has not been well enough documented, and little is known on their current distribution. This study determined the current spatial distribution, abundance, diversity, and seasonal variations of tsetse flies in and around the Akagera National Park. Methods A longitudinal stratified sampling following the seasons was used. Biconical traps were deployed in 55 sites for 6 consecutive days of each study month from May 2018 to June 2019 and emptied every 48 h. Flies were identified using FAO keys, and the number of flies per trap day (FTD) was used to determine the apparent density. Pearson chi-square (χ2) and parametrical tests (t-test and ANOVA) were used to determine the variations between the variables. The significance (p < 0.05) at 95% confidence interval was considered. Logistic regression was used to determine the association between tsetse occurrence and the associated predictors. Results A total of 39,516 tsetse flies were collected, of which 73.4 and 26.6% were from inside Akagera NP and the interface area, respectively. Female flies accounted for 61.3 while 38.7% were males. Two species were identified, i.e. G. pallidipes [n = 29,121, 7.4 flies/trap/day (FTD)] and G. morsitans centralis (n = 10,395; 2.6 FTD). The statistical difference in numbers was significant between the two species (p = 0.000). The flies were more abundant during the wet season (15.8 FTD) than the dry season (4.2 FTD). Large numbers of flies were trapped around the swamp areas (69.1 FTD) inside the park and in Nyagatare District (11.2 FTD) at the interface. Glossina morsitans was 0.218 times less likely to occur outside the park. The chance of co-existing between the two species reduced outside the protected area (0.021 times). Conclusions The occurrence of Glossina seems to be limited to the protected Akagera NP and a narrow band of its surrounding areas. This finding will be crucial to design appropriate control strategies. Glossina pallidipes was found in higher numbers and therefore is conceivably the most important vector of trypanosomosis. Regional coordinated control and regular monitoring of Glossina distribution are recommended. Graphic Abstract

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Modelling movement and mortality: killing tsetse flies in the field

Computers and Electronics in Agriculture ◽

10.1016/0168-1699(95)00022-v ◽

1995 ◽

Vol 13 (2) ◽

pp. 155-175 ◽

Cited By ~ 1

Author(s):

Brian Williams

Keyword(s):

Tsetse Flies

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Anal Feeding as a Method of Infecting Tsetse Flies withTrypanosoma Gambiense

Annals of Tropical Medicine and Parasitology ◽

10.1080/00034983.1961.11686017 ◽

1961 ◽

Vol 55 (1) ◽

pp. 46-48 ◽

Cited By ~ 2

Author(s):

D. J. B. Wijers ◽

W. A. McDonald

Keyword(s):

Tsetse Flies

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Aircraft Applications of Insecticides in East Africa. IV.—The Application of Coarse Aerosols in Savannah Woodland containing the Tsetse Flies Glossina morsitans and G. swynnertoni

Bulletin of Entomological Research ◽

10.1017/s0007485300024615 ◽

1953 ◽

Vol 44 (4) ◽

pp. 627-640 ◽

Cited By ~ 17

Author(s):

K. S. Hocking ◽

H. C. M. Parr ◽

D. Yeo ◽

D. Anstey

Keyword(s):

East Africa ◽

Meteorological Conditions ◽

The Other ◽

Tsetse Flies ◽

Small Populations ◽

Central Province ◽

Glossina Morsitans ◽

Short Period ◽

Savannah Woodland ◽

Mass Median

Attempts have been made to eradicate the tsetse flies G. morsitans and G. swynnertoni from two blocks of savannah woodland situated in the Central Province of Tanganyika.The insecticides were applied from aircraft. Coarse aerosols were used, with mass median diameters of approximately 90 microns; droplet diameters varied from 4 microns to 250 microns approximately.Eight applications of insecticides were made at intervals of two weeks. Each application was carried out at a nominal dosage of 0·25 gallons per acre, which was equivalent to 0·20 1b. per acre of the p, p'isomer of DDT or 0·03 lb. per acre of the γ isomer of BHC.In the area treated with DDT it is possible that both species of flies were eradicated for a short period, but small populations were re-established there by immigrant flies. In the other block the reduction was not so great, but it is not considered that this was due to a lesser effectiveness of the BHC, but to a combination of circumstances that led to less effective applications.Some general observations are made upon the use of aircraft for this sort of work, particularly in connection with the effect of meteorological conditions.

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