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Showing papers on "Bulinus truncatus published in 1985"


Journal ArticleDOI
01 Jan 1985
TL;DR: The ethyl acetate extracts of fruits and bark of Acacia nilotica, tomentosa and astringens, showed the highest molluscicidal activity against snail species Bulinus truncatus and Biomphalaria pfeifferi.
Abstract: The ethyl acetate extracts of fruits and bark of Acacia nilotica (L.) Willd. ex Del subsp. nilotica, tomentosa and astringens, showed the highest molluscicidal activity against snail species Bulinus truncatus and Biomphalaria pfeifferi. This was due mainly to the flavanol derivatives isolated from the tannin extracts and characterized as (-)-epigallocatechin-7-gallate and (-)-epigallocatechin-5,7-digallate. It was found also that the ethyl acetate extracts of 20 Acacia species and subspecies growing in the Sudan were active against the snails, which was due to the presence of the above mentioned (-)-epigallocatechin derivatives.

26 citations


Journal Article
TL;DR: Snail numbers were reduced by mollusciciding and/or weed clearance in four canals, but outside the focal target canal stretches the weed clearance alone did not substantially reduce the snail populations.
Abstract: All 38 minor canals in a limited area of the Gezira Irrigated Area were surveyed four times over a 2-year period to determine the aquatic and semi-aquatic vegetation types found and their distribution. A more detailed 2-year study of the correlation between snail density and aquatic vegetation was carried out in 18 of these canals. A total of 22 different species of weed were recorded, with floating and submerged weeds being more widespread and dense in the clear, slow-moving water at the end of the irrigation season in March/April, than in the turbid flood waters in October. The schistosome vector snails Biomphalaria pfeifferi and Bulinus truncatus were found in conjunction with aquatic weeds and B. pfeifferi in particular increased in numbers as weed growth continued. In the second season of the study when mechanical weed clearing and regular focal mollusciciding was being carried out there was a noticeable reduction in weed density but repopulation was rapid. Snail numbers were reduced by mollusciciding and/or weed clearance in four canals, but outside the focal target canal stretches the weed clearance alone did not substantially reduce the snail populations.

19 citations


Journal Article
TL;DR: In a 14-month study, 128 765 Bulinus truncatus snails were collected from canals located near four villages in the northern part of the Gezira Irrigated Area, and were examined for patent trematode infections, by exposure to light as mentioned in this paper.
Abstract: During this 14-month study, 128 765 Bulinus truncatus snails were collected from canals located near four villages in the northern part of the Gezira Irrigated Area, and were examined for patent trematode infections, by exposure to light. In all, 903 shedded cercariae, of which 424 were identified as S. haematobium, and one village, Bashagra, was the source of 80% of these S. haematobium infections. The highest density of snails occurred from March to May and the peak of snail infections occurred from June through August. The residents of the four villages and any adjacent small camps were examined for infection with S. mansoni and/or S. haematobium by collecting and examining stool and urine samples. The overall prevalences were 50% for S. mansoni and 20% for S. haematobium. The age prevalence curves were very different, with the prevalence of S. haematobium falling off more sharply in the over-20 age groups than was the case with S. mansoni. Observations at the human water contact sites suggested that the transmission of S. haematobium was increased when the canals contained shallow stagnant water, when the temperature was above 26 degrees C, and when the site was frequented by small children (particularly boys aged 5-15), for swimming. Our data suggest that at any site the transmission period is short and seasonal.

9 citations


Journal Article
TL;DR: Extracts of the Acacia nilotica subspecies may be promising vegetable molluscicides against the two snail species which transmit schistosomiasis in the Sudan.
Abstract: The acetone, alcohol and aqueous extracts of the fruits and stem bark of Acacia nilotica subspp. tomentosa, astringens and nilotica showed molluscicidal activity against the two snail species which transmit schistosomiasis in the Sudan. Being effective against Bulinus truncatus and Biomphalaria pfeifferi, extracts of the Acacia nilotica subspecies may be promising vegetable molluscicides.

3 citations