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 ◽  
...  

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.

1976 ◽  
Vol 66 (4) ◽  
pp. 731-744 ◽  
Author(s):  
G. A. Vale ◽  
J. W. Hargrove ◽  
A. M. Jordan ◽  
P. A. Langley ◽  
A. R. Mews

AbstractMale and female Glossina morsitans morsitans Westw. which emerged from puparia produced by animal-fed and in vitro-fed colonies in England were marked distinctively with non-toxic paint and released into a natural habitat of G. morsitans and G. pallidipes Aust. in Rhodesia. Concurrently, adults of both species which emerged from locally-collected puparia were marked and released. Recaptures from artificial refuges, odour attractants and mobile baits at periods up to 59 days after release and at distances up to 1800 m from the release site indicated no clear differences between native G. morsitans and the two laboratory-reared groups in respect of body size, amount of fat present at emergence, survival, dispersal, availability to a range of baits, diet, speed of taking a first meal, wing damage and insemination rate. Although the blood-meal identifications for marked female G. morsitans were similar to those for both sexes of unmarked flies, blood-meals from marked males showed a relatively high proportion of bovid identifications. Unmarked flies caught were generally older than marked catches. The ratio of females to males in unmarked samples (1:1 for G. morsitans, 2:1 for G. pallidipes) was roughly double that in marked catches.


Author(s):  
Kalinga Chilongo ◽  
Tawanda Manyangadze ◽  
Samson Mukaratirwa

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.


2002 ◽  
Vol 80 (7) ◽  
pp. 1149-1155 ◽  
Author(s):  
W G Evans ◽  
R H Gooding

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.


1991 ◽  
Vol 81 (3) ◽  
pp. 323-331 ◽  
Author(s):  
G. A. Vale

AbstractField studies in Zimbabwe elucidated how trees might be enhanced as baits for controlling Glossina morsitans morsitans Westwood and G. pallidipes Austen. Catches from electrocuting devices at the bases of trees were near nil when sampling tsetse flies landing on the trunk but much greater when sampling them flying within 1 m of the trunk. Catches increased 5–8 times when 2 m2 of the trunk were blackened and given odour of acetone, 1-octen-3-ol, 3-n-propyl phenol and 4-methyl phenol, but were still only ca. 30% of the catches from an odour-baited, free-standing, 1 × 1 m screen of black cloth. The upright trunk of real and model trees hindered their attractiveness but leaves and branches 5 m above ground had no clear effect. Real and artificial stumps of trees were as effective as the screen if they were 1 m2, compact and sharply outlined. The practical and biological implications of the results are discussed, with particular reference to the use of insecticide-treated netting with modified tree stumps as baits for control.


1980 ◽  
Vol 58 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Jon G. Houseman

The anterior midgut of Glossina morsitans morsitans Westwood contains a proteinase inhibitor, molecular weight 5000 ± 2000daltons, stable to 1 M HCl, heat, and dialysis, but unstable to 1% trichloroacetic acid. Inhibitor activity is not associated with anticoagulant in the anterior midgut. The specific activity of the proteinase inhibitor is similar in mated and unmated females and greater than in male tsetse flies. Proteinase inhibitor inhibits proteinase VI and trypsin hydrolysis of N-benzoyl-L-arginine ethyl ester (BAEE) and benzoyl-DL-arginine-p-nitroanilide (BAPNA) but has no effect on proteinase VI hydrolysis of haemoglobin. Inhibition of trypsin hydrolysis of haemoglobin is noncompetitive. Proteinase inhibitor levels in the anterior midgut decreased immediately after feeding and then increased, reaching a maximum 60–100 h after ingestion of the bloodmeal. Postteneral flies contained higher levels of proteinase inhibitor than teneral individuals. Trypsin activity in gut homogenates of Phormia regina and Aedes aegypti was inhibited by the tsetse inhibitor. There was no detectable inhibition of bovine or Pterostichus adstrictus trypsin activity. Inhibition of Periplaneta americana trypsin occurred but was less than fly trypsin inhibition. The possible role of the inhibitor in terminating proteinase production is discussed.


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 ◽  
...  

1988 ◽  
Vol 78 (2) ◽  
pp. 293-300 ◽  
Author(s):  
G. A. Vale ◽  
D. R. Hall ◽  
A. J. E. Gough

AbstractIn Zimbabwe, catches of Glossina morsitans morsitans Westwood and G. pallidipes Austen in traps baited with acetone and 1-octen-3-ol were increased by the addition of the synthetic mixture of eight phenols found in cattle urine to a level equal to or greater than those with natural urine. The addition of natural urine to the synthetic mixture did not increase catches further, indicating that the phenols account for essentially all the attractiveness of cattle urine. 4-Methylphenol and 3-n-propylphenol were shown to be the naturally-occurring components essential for attractiveness, and 2-methoxyphenol was found to reduce attractiveness. 4-Methylphenol alone was slightly attractive to both species, but only for males, increasing catches by approximately 30%. Catches of both species were increased by approximately 50% by 3-n-propylphenol. The addition of 4-methylphenol increased catches of G. pallidipes by up to a further four times, but catches of G. m. morsitans were decreased. Of 14 other phenols tested, phenol, 3-methylphenol and 4-ethylphenol increased the attractiveness of 3-n-propylphenol to G. pallidipes without decreasing the attractiveness to G. m. morsitans; (E)- and (Z)-3-(1-propenyl)phenol, potential contaminants in 3-n- propylphenol, did not reduce the attractiveness of mixtures of 3-n-propylphenol and 4-methylphenol, and the E and, to a lesser extent, the Z isomer could substitute for 3-n-pro-pylphenol in these mixtures. Mixtures of phenols which increased the attractiveness of traps to tsetse showed similar effects with targets but at a slightly reduced level.


1981 ◽  
Vol 71 (2) ◽  
pp. 259-265 ◽  
Author(s):  
G. A. Vale

AbstractIn Zimbabwe, field studies were made of the extent to which catches of Glossina morsitans morsitans Westw. and G. pallidipes Aust. from stationary visual targets plus ox odour were changed by maintaining the ox on normal, starving or fattening diets. A fattening diet after a week of starvation often produced a several-fold increase in catches in a few days, followed by a declining catch associated with lack of appetite, and a further increase in catch when appetite was restored. Carbon dioxide and acetone emitted by the oxen could not account fully for the level and variations of catches.


1982 ◽  
Vol 72 (1) ◽  
pp. 95-106 ◽  
Author(s):  
G. A. Vale

AbstractBased on previous studies of the trap-orientated behaviour of Diptera, a variety of new traps was designed to maximise the speed and probability of capturing Glossina morsitans morsitans Westw. and G. pallidipes Aust. arriving near traps, and to minimise the probability of capturing other flies. In Zimbabwe, catches were made with these traps in the presence and absence of carbon dioxide and acetone as odour attractants, leading to the identification of a simple trap for which the probability of capturing Glossina spp. was up to twice as great as it was for a standard biconi-cal trap, and for which the probability of capturing other Diptera was very much less than it was for the biconical trap. The probability of capture by the simple trap was 100% for G. pallidipes, 51% for G. m. morsitans, 6% for Stomoxyinae and 1% for non-biting Muscidae. Half the tsetse that arrived near the simple trap were captured within 5 min of arrival. The number of tsetse that contacted simple targets designed to expose flies to insecticide amounted to 32–263% of the catches of a biconical trap. The use of traps and targets for tsetse control, and the procedures for trap improvement, are discussed.


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