Anterior midgut proteinase inhibitor from Glossina morsitans morsitans Westwood (Diptera: Glossinidae) and its effects upon tsetse digestive enzymes

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.

1977 ◽  
Vol 55 (1) ◽  
pp. 215-222 ◽  
Author(s):  
R. H. Gooding

There was a significant positive correlation between protein content and the amounts of trypsin and carboxypeptidase B (CPB) in the digestive portion of the midgut of Glossina morsitans morsitans, 24, 48, 72, and 96 h after feeding on a rabbit. CPB and trypsin activity were also positively correlated. Trypsin and CPB production were stimulated, to varying degrees, by bovine serum albumin (BSA), α-globulin, β-globulin, γ-globulin, and haemoglobin; the greatest response was to BSA. Peptides derived from BSA by trypsin cleavage also stimulated production of trypsin and CPB.


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.


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.


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.


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.


1979 ◽  
Vol 69 (1) ◽  
pp. 183-193 ◽  
Author(s):  
G. A. Vale ◽  
J. W. Hargrove

AbstractAn incomplete ring of electrified nets was placed round a trap or round an electrified net and visual target in woodland infested with Glossina morsitans morsitans Westw. and G. pallidipes Aust. in Rhodesia. The distribution of catches in these systems was used to estimate the minimum efficiencies with which the trap or net and target captured flies that were initially attracted by odours derived from a herd of cattle hidden below ground. With mature tsetse, the estimates for the trap were 23 and 21% for male and female G. morsitans, respectively, and 70 and 49% for male and female G. pallidipes. For the net and target, the corresponding figures were 29, 30, 53 and 43. The coefficient of variation of such estimates (about 10%) was low enough to suggest that the technique affords a quick and reliable means of screening the efficiency of many trap designs. Factors responsible for the efficiency of the trap were elucidated. Data for other insects were obtained.


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