scholarly journals Effects of Human Settlements and Spatial Distribution of Wing Vein Length, Wing Fray Categories and Hunger Stages in Glossina morsitans morsitans (Diptera: Glossinidae) and Glossina pallidipes (Diptera: Glossinidae) in Areas Devoid of Cattle in North-Eastern Zambia

2020 ◽  
Author(s):  
Kalinga Chilongo ◽  
Tawanda Manyangadze ◽  
Samson Mukaratirwa
Keyword(s):  
Glossina Pallidipes ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Human Settlement ◽  
Glossina Morsitans ◽  
Human Settlements ◽  
Wing Vein ◽  
Transect Line ◽  
North Eastern ◽  
Inner Parts

Abstract The effect of human-associated habitat degradation on tsetse populations is well established. However, more insights are needed into how gradual human encroachment into tsetse fly belts affect tsetse populations. This study investigated how wing vein length, wing fray categories, and hunger stages, taken as indicators of body size, age, and levels of access to hosts, respectively, in Glossina morsitans morsitans Westwood (Diptera: Glossinidae) and Glossina pallidipes Austen (Diptera: Glossinidae), varied along a transect from the edge into inner parts of the tsetse belt, in sites that had human settlement either concentrated at the edge of belt or evenly distributed along transect line, in north-eastern Zambia. Black-screen fly round and Epsilon traps were used in a cross-sectional survey on tsetse flies at three sites, following a transect line marked by a road running from the edge into the inner parts of the tsetse belt, per site. Two sites had human settlement concentrated at or close to the edge of the tsetse belt, whereas the third had human settlement evenly distributed along the transect line. Where settlements were concentrated at the edge of tsetse belt, increase in distance from the settlements was associated with increase in wing vein length and a reduction in the proportion of older, and hungry, tsetse flies. Increase in distance from human settlements was associated with improved tsetse well-being, likely due to increase in habitat quality due to decrease in effects of human activities.

scholarly journals Responses of Glossina pallidipes and Glossina morsitans morsitans tsetse flies to analogues of δ-octalactone and selected blends

Acta Tropica ◽  
2016 ◽  
Vol 160 ◽  
pp. 53-57 ◽  
Author(s):  
Benson M. Wachira ◽  
Paul O. Mireji ◽  
Sylvance Okoth ◽  
Margaret M. Ng’ang’a ◽  
Julius M. William ◽  
...  
Keyword(s):  
Glossina Pallidipes ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Glossina Morsitans

Integration of insect sterility and insecticides for control of Glossina morsitans morsitans Westwood (Diptera: Glossinidae) in Tanzania. III. Test site characteristics and the natural distribution of tsetse flies

1983 ◽  
Vol 73 (3) ◽  
pp. 373-381 ◽  
Author(s):  
D. B. Gates ◽  
P. E. Cobb ◽  
D. L. Williamson ◽  
B. Bakuli ◽  
D. A. Dame ◽  
...  
Keyword(s):  
Release Site ◽  
Test Site ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Detailed Data ◽  
Glossina Morsitans ◽  
Natural Distribution ◽  
Male Density ◽  
Site Characteristics ◽  
North Eastern

AbstractDetailed data from a preselected release site in Tanzania were collected preparatory to testing the insect sterility concept against Glossina morsitans morsitans Westw. The site was at Mkwaja Ranch, a north-eastern coastal cattle-ranching enterprise, in which about 195 km2 was encompassed by a 1-km-wide fly barrier constructed at an average cost of $37/ha. Weekly surveys of flyround transects spaced 1 km apart were conducted over a 14-month period. The estimated male density of G. m. morsitans in the release site was about 630/km2 and for G. pallidipes Aust., 255/km2. The only other species of tsetse found was G. brevipalpis Newst., which was restricted to drainage areas during periods of low rainfall.

Seasonal variation in nutritional levels of male tsetse flies Glossina morsitans morsitans (Diptera: Glossinidae) caught using fly-rounds and electric screens

1999 ◽  
Vol 89 (4) ◽  
pp. 381-387 ◽  
Author(s):  
P. Van den Bossche ◽  
J.W. Hargrove
Keyword(s):  
Dry Weight ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Feeding Rates ◽  
Cool Season ◽  
Glossina Morsitans ◽  
Wing Vein ◽  
Annual Cycles ◽  
Hot Dry Season ◽  
Highly Correlated

AbstractA total of 4420 male Glossina morsitans morsitans Westwood were captured on man fly-rounds in Katete District, Eastern Province, Zambia between February 1991 and December 1993. Of these flies, 1680 were captured before June 1992, during which period 989 flies were also captured on odour-baited electric screens operated in the same area. Non-teneral flies were analysed for fat, haematin and residual dry weight and their wing-vein length was measured. There were well marked annual cycles in wing length, fat and residual dry weight. Flies were biggest at the end of the rainy season, and smallest at the end of the hot dry season. Fat levels were lowest before the onset of the rains and highest in the cool season. Residual dry weight was a function of haematin content and the degree of wing-fray; these factors were used to correct the residual dry weight to zero haematin. Corrected residual dry weight and wing-vein lengths were most highly correlated with relative humidity in the month prior to capture (r > 0.8 and 0.6 respectively). Correlations with saturation deficit were weaker; temperature accounted for <20% of the variance. Fly-round flies had a consistently higher residual dry weight than those from the electric screen, but their fat levels were lower. The distributions of log haematin levels differed little between the two sampling methods and were adequately described by a model where capture and feeding rates increased exponentially after each meal. The increase in the feeding rate after each meal differed little with season and was closely similar to that estimated for female G. pallidipesAusten in Zimbabwe.

scholarly journals Characterization and Tissue Tropism of Newly Identified Iflavirus and Negeviruses in Glossina morsitans morsitans Tsetse Flies

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2472
Author(s):  
Irene K. Meki ◽  
Hannah-Isadora Huditz ◽  
Anton Strunov ◽  
René A. A. van der Vlugt ◽  
Henry M. Kariithi ◽  
...  
Keyword(s):  
Mass Production ◽  
Glossina Pallidipes ◽  
Glossina Morsitans Morsitans ◽  
Viral Transmission ◽  
Tsetse Flies ◽  
Tissue Tropism ◽  
Helicase Domain ◽  
Glossina Morsitans ◽  
Methyltransferase Domain ◽  
The Impact

Tsetse flies cause major health and economic problems as they transmit trypanosomes causing sleeping sickness in humans (Human African Trypanosomosis, HAT) and nagana in animals (African Animal Trypanosomosis, AAT). A solution to control the spread of these flies and their associated diseases is the implementation of the Sterile Insect Technique (SIT). For successful application of SIT, it is important to establish and maintain healthy insect colonies and produce flies with competitive fitness. However, mass production of tsetse is threatened by covert virus infections, such as the Glossina pallidipes salivary gland hypertrophy virus (GpSGHV). This virus infection can switch from a covert asymptomatic to an overt symptomatic state and cause the collapse of an entire fly colony. Although the effects of GpSGHV infections can be mitigated, the presence of other covert viruses threaten tsetse mass production. Here we demonstrated the presence of two single-stranded RNA viruses isolated from Glossina morsitans morsitans originating from a colony at the Seibersdorf rearing facility. The genome organization and the phylogenetic analysis based on the RNA-dependent RNA polymerase (RdRp) revealed that the two viruses belong to the genera Iflavirus and Negevirus, respectively. The names proposed for the two viruses are Glossina morsitans morsitans iflavirus (GmmIV) and Glossina morsitans morsitans negevirus (GmmNegeV). The GmmIV genome is 9685 nucleotides long with a poly(A) tail and encodes a single polyprotein processed into structural and non-structural viral proteins. The GmmNegeV genome consists of 8140 nucleotides and contains two major overlapping open reading frames (ORF1 and ORF2). ORF1 encodes the largest protein which includes a methyltransferase domain, a ribosomal RNA methyltransferase domain, a helicase domain and a RdRp domain. In this study, a selective RT-qPCR assay to detect the presence of the negative RNA strand for both GmmIV and GmmNegeV viruses proved that both viruses replicate in G. m. morsitans. We analyzed the tissue tropism of these viruses in G. m. morsitans by RNA-FISH to decipher their mode of transmission. Our results demonstrate that both viruses can be found not only in the host’s brain and fat bodies but also in their reproductive organs, and in milk and salivary glands. These findings suggest a potential horizontal viral transmission during feeding and/or a vertically viral transmission from parent to offspring. Although the impact of GmmIV and GmmNegeV in tsetse rearing facilities is still unknown, none of the currently infected tsetse species show any signs of disease from these viruses.

The dispersion of active Glossina morsitans morsitans Westwood and G. pallidipes Austen (Diptera: Glossinidae) near a large tree and an assessment of the capturing method used

1980 ◽  
Vol 70 (3) ◽  
pp. 455-466 ◽  
Author(s):  
R. J. Phelps ◽  
N. G. Chapman
Keyword(s):  
Glossina Pallidipes ◽  
Glossina Morsitans Morsitans ◽  
Diurnal Variations ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Late Afternoon ◽  
Large Tree ◽  
Hot Dry Season ◽  
Different Seasons ◽  
Representative Samples

AbstractLarge electrocuting nets were used at different seasons near a big tree in Zimbabwe to capture tsetse flies at different heights, distances from the bole and times of day. Some differences were found between species and sexes, but most flies were caught within 3·3 m of the ground and in the late afternoon. In the cool and wet seasons, Glossina pallidipes Aust. was less confined to lower levels than was G. morsitans morsitans Westw. Flies, especially fed males of G. pallidipes near the bole of the tree, were recorded in the greatest numbers in the midday period. Diurnal variations occurred in the relative proportions of females of the two species caught at different points. Releasing ox odour through an electrocuting net suspended at different heights confirmed that most flies were flying near the ground, especially in the hot dry season. Comparison of samples from the large electrocuting nets with those caught by other methods operated contemporaneously showed that the large nets gave samples which compared well with those from an electrocuting screen used in conjunction with a ventilated pit. Methods involving fly-capture by people gave very distorted results for all catch parameters examined. No method used gave consistently representative samples of replete flies or of newly emerged flies.

Responses of tsetse flies, Glossina morsitans morsitans and Glossina pallidipes, to baits of various size

2011 ◽  
Vol 25 (4) ◽  
pp. 365-369 ◽  
Author(s):  
S. J. TORR ◽  
A. CHAMISA ◽  
G. A. VALE ◽  
M. J. LEHANE ◽  
J. M. LINDH
Keyword(s):  
Glossina Pallidipes ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Glossina Morsitans

scholarly journals Effect of wing length on the prevalence of trypanosomes in Glossina morsitans morsitans in eastern Zambia

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Cornelius Mweempwa ◽  
Kalinga Chilongo ◽  
Kyoko Hayashida ◽  
Boniface Namangala
Keyword(s):  
Wing Length ◽  
Predictor Variable ◽  
Principal Component ◽  
Population Data ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Wing Vein ◽  
Data Set ◽  
Combining Data

Abstract Background Tsetse flies (Diptera: Glossinidae) transmit trypanosomiasis (sleeping sickness in humans and nagana in livestock). Several studies have indicated that age, sex, site of capture, starvation and microbiome symbionts, among others, are important factors that influence trypanosome infection in tsetse flies. However, reasons for a higher infection rate in females than in males still largely remain unknown. Considering that tsetse species and sexes of larger body size are the most mobile and the most available to stationary baits, it was hypothesized in this study that the higher trypanosome prevalence in female than in male tsetse flies was a consequence of females being larger than males. Methods Black screen fly rounds and Epsilon traps were used to collect tsetse flies in eastern Zambia. Measurement of wing vein length and examination for presence of trypanosomes in the flies were carried out by microscopy. Principal component method was carried out to assess the potential of wing vein length as a predictor variable. The multilevel binary logistic regression method was applied on whole data, one-method data and one-sex data sets to evaluate the hypothesis. Results Data derived from a total of 2195 Glossina morsitans morsitans were evaluated (1491 males and 704 females). The wing length variable contributed the highest variance percentage (39.2%) to the first principal component. The variable showed significant influence on prevalence of trypanosomes when the analysis was applied on the whole data set, with the log odds for the prevalence of trypanosomes significantly increasing by 0.1 (P  =  0.032), per unit increase in wing length. Females had higher trypanosome prevalence rates than males, though not always significant. Furthermore, moving from females to males, wing length significantly reduced by 0.2 (P  <  0.0001). Conclusions We conclude that wing length is an important predictor variable for trypanosome prevalence in Glossina morsitans morsitans and could partially explain the higher prevalence of trypanosomes in females than in males. However, reasonably representative population data are required for analysis—a serious challenge with the current tsetse sampling methods. Thus, analysis combining data from mobile and stationary methods that include both sexes' data could be useful to verify this hypothesis. Graphical abstract

Turbulent plumes of heat, moist heat, and carbon dioxide elicit upwind anemotaxis in tsetse flies Glossina morsitans morsitans Westwood (Diptera: Glossinidae)

2002 ◽  
Vol 80 (7) ◽  
pp. 1149-1155 ◽  
Author(s):  
W G Evans ◽  
R H Gooding
Keyword(s):  
Carbon Dioxide ◽  
Wind Tunnel ◽  
Relative Humidity ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Low Velocity ◽  
Upwind Flight ◽  
Moist Heat ◽  
Heated Air

The roles and interactions of turbulent plumes of heat, moist heat, and carbon dioxide in mediating upwind flight of adult tsetse flies (Glossina morsitans morsitans Westwood) were investigated using a wind tunnel in a constant-environment chamber. Heat fluctuations in the plume that were detected by a thermocouple and displayed as oscilloscope traces allowed direct visualization of the structures of the plumes. Significantly more flies flew upwind when exposed to plumes of (i) carbon dioxide (0.0051% above background) and air (58% relative humidity) compared with air alone; (ii) carbon dioxide and heated air (35% relative humidity and temperature fluctuating up to 0.09°C above background) compared with carbon dioxide and air; and (iii) carbon dioxide and moist (82% relative humidity) heated air (temperature fluctuating up to 0.05°C above background) compared with carbon dioxide and heated air. However, there were no significant differences in upwind flight of flies exposed to plumes of (i) air compared with humidified air (65% relative humidity); (ii) carbon dioxide and heated air compared with heated air alone; and (iii) carbon dioxide and moist heated air compared with moist heated air alone. Recorded temperature fluctuations in heat plumes transported downwind from a tethered steer in a pasture showed patterns similar to those produced in the wind-tunnel plumes. These results suggest that host emissions of carbon dioxide alone and combined heat and moisture carried downwind by low-velocity winds elicit upwind anemotaxis in tsetse flies, which distinguish these emissions from a background of lower atmospheric levels.

Aircraft Applications of Insecticides in East Africa. VI.—Applications of a coarse Aerosol containning DDT to control the Tsetse Flies, Glossina morsitans Westw., Glossina swynnertoni Aust. and Glossina pallidipes Aust.

1954 ◽  
Vol 45 (3) ◽  
pp. 585-603 ◽  
Author(s):  
K. S. Hocking ◽  
D. Yeo ◽  
D. G. Anstey
Keyword(s):  
Random Effects ◽  
Glossina Pallidipes ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Median Diameter ◽  
Coarse Aerosol ◽  
Savannah Woodland ◽  
Mass Median ◽  
Glossina Swynnertoni ◽  
Mass Median Diameter

An experiment is described where applications of a coarse aerosol were made to savannah woodland containing the tsetse flies, Glossina moritans Westw., G. swynnertoni Aust. and G. pallidipes Aust.Seven applications were made, each at a nominal dosage of 0·25 lb. of technical DDT per acre and 0·25 gallons of solution per acre. The applications in any particular part of the treaed woodland covered an interval of 90 days, or rather more than two pupal periods.The coarse aerosol was produced by emitting the insecticidal solution under pressure through fine nozzles fitted to a boom. It had a mass median diameter of approximately 60 microns, and droplet dismeters varied from a few microns to approximately 200 microns.The population of G. pallidipes was so drastically reduced that it has subsequently dies out. The reduction of G. morsitans was approximately 95 per cent. The differences between the reductions are attributed mainly to differences between the ease with which the three species can be killed. It is pointed out that this is not necessarily equivalent to differences in susceptibility.Comparisons are made with previous experiments, and the different results of the various experiments are difficult to explian satisfactory. The increased cover in savannah areas during the leafy period may have reduced the effectiveness of the applications, and the total periods covered by the various series of applications were probably also important. Random effects, leading to ineffective treatments, may also be important.Costs are discussed.

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