José Pedro Pereira

Influência de diversos derivados de vegetais na sobrevida das larvas de Aedes fluviatilis(Lutz) (Diptera: Culicidade) em laboratorio

The larvicidal properties of 34 plant extracts were tested against Aedes fluviatilis (Lutz) (Diptera: Culicidae) larvae, at 100, 10 and 1 ppm concentrations; 26.6% of the extracts enhanced larval mortality (alpha = 0.05) at 100 ppm (Anacardium occidentale, Agave americana, Allium sativum, Coriandrum sativum, Nerium oleander, Spatodea campanulata, Tibouchina scrobiculata and Vernonia salzmanni). Anacardic acid (A. occidentale) was effective at 10 ppm and A. sativum (crude extract) at 1 ppm.The larvicidal properties of 34 plant extracts were tested against Aedes fluviatilis (Lutz) (Diptera: Culicidae) larvae, at 100, 10 and 1 ppm concentrations; 26,6% of the extracts enhanced larval mortality (x = 0,05) at 100 ppm (Anacardium occidentale, Agave americana, Allium sativum, Coriandrum sativum, Nerium oleander, Spatodea campanulata, Tibouchina serobiculata and Vernonia salzmanni). Anacardic acid (A. occidentale) was effective at 10 ppm and A. sativum (crude extract) at 1 ppm.

O uso da casca da castanha do caju, Anacardium occidentale, como moluscicida alternativo

Bioassays using hexanolic extracts of cashew nut shells, of Anacardium occidentale, collected in Ceara in 1972 (Sample 1) and 1987 (Sample 2) were undertaken with adult snails and egg masses of Biomphalaria glabrata, B. tenagophila and B. straminea both in the laboratory and in the field. Non extracted shells, 18.5 g, sample 1, were also tested with adult snails and egg masses of the three species. The toxicity of extract was tested with fish (Poecilia reticulata) and tadpoles. The lethal concentration, CL90, of sample 1 was from 2.0 to 2.2 ppm for adult snails of the three species. With sample 2, the CL90 was 2.0, 0.5 and 30.0 ppm for B. glabrata adults, newly hatched snails and egg mass respectively. Non extracted shells caused 40 - 80% mortality of adult snails, 22 - 35% mortality of embryos and 40 - 55% reduction of egg production. The hexanolic extract, sample 2, were inocuous for tadpole and fish at 2 ppm. In the field, in pools of still water treatment with 20 ppm of extract, sample 1, caused a 97.1% mortality of B. straminea and 100% mortality of B. glabrata and B.tenagophila. Using Niclosamide, at 3 ppm, 100% mortality of the three species occured.

Ensaios preliminares em laboratório para verificar a ação moluscicida de algumas espécies da flora brasileira

Estudou-se em laboratorio a atividade moluscicida de 68 extratos de 23 plantas brasileiras. As solucoes em agua desclorada dos extratos hexânicos e etanolico, nas concentracoes de 1, 10 e 100 ppm, foram testadas sobre caramujos adultos e desovas de Biomphalaria glabrata, criados em laboratorio. As plantas que demonstraram acao moluscicida na concentracao de 100 ppm foram: Arthemisia verlotorum Lamotte, Caesalpinia peltophoroides Benth, Cassia rugosa G.Don., Eclipta alba Hassk, Euphorbia pulcherrima Willd, Euphorbia splendens Bojer, Joannesia princeps Vell, Leonorus sibiricus L.,Macrosiphonia guaranitica Muell,Nerium oleander L., Palicourea nicotianaefolia Cham, e Schlech., Panicum maximum M., Rumex crispus L., Ruta graveolens L., e Stryphnodendron barbatiman M.Estudou-se em laboratorio a atividade moluscicida de 68 extratos de 23 plantas brasileiras. As solucoes em agua desclorada dos extratos hexânicos e etanolico, nas concentracoes de 1, 10 e 100 ppm, foram testadas sobre caramujos adultos e desovas de Biomphalaria glabrata, criados em laboratorio. As plantas que demonstraram acao moluscicida na concentracao de 100 ppm foram: Arthemisia verlotorum Lamotte, Caesalpinia peltophoroides Benth, Cassia rugosa G.Don., Eclipta alba Hassk, Euphorbia pulcherrima Willd, Euphorbia splendens Bojer, Joannesia princeps Vell, Leonorus sibiricus L.,Macrosiphonia guaranitica Muell,Nerium oleander L., Palicourea nicotianaefolia Cham, e Schlech., Panicum maximum M., Rumex crispus L., Ruta graveolens L., e Stryphnodendron barbatiman M.

Atual distribuição geográfica dos moluscos hospedeiros intermediários do Schistosoma mansoni em Belo Horizonte, MG, Brasil

Malacological surveys were conducted in Belo Horizonte with a view to obtain new data on the distribution and density of schistosomose bearing snails and their natural rate of infection by Schistosoma mansoni. Of 3.261 Biomphalaria glabrata collected during 1979-81, 100 (3,1%) were found naturally infected. One hundred and two water collections were surveyed and 36 (35%) were found harboring the mentioned snail species (23 of them in the watershed of Pampulha, 13 in the tributaires of the Arrudas creek). The species B. tenagophila was found in two waterbodies, and B. straminea in two other. Other snail species collected were Pomacea haustrum, Physa sp and Drepanotrema cimex. Data of this survey were compared with data published in 1967 and 50% reduction in the snail breeding places was observed. This reduction was due mainly to public works and engineering activities accompanying the growth of city. Schistosomiasis is still present in the periphery of the city and only engineering works will be able to eliminate this health problem.

The prolonged use of niclosamide as a molluscicide for the control of Schistosoma mansoni

Applications of niclosamide at three-monthly intervals were undertaken for 14 years in foci of Biomphalaria glabrata in the water sources of Peri-Peri (Capim Branco, MG). All the residents of the area were submitted to an annual fecal examination (Kato/Katz) and those individuals eliminating Schistosoma mansoni eggs were treated with oxamniquine. A malacological survey was undertaken at three-monthly intervals by means of ten scoops with a perforated ladle each ten metres along the two banks of the ditches and streams of the region. Where snails were found, molluscicide was applied by means of dripping or aspersion using a 3 ppm aqueous suspension of niclosamide. Initially, a mean of 14.3% of snails in the region were found to be eliminating cercariae. Following the first four applications of molluscicide, this was reduced to 0.0% and maintained at about 1.5% throughout the program. Thus, there was a continued possibility of schistosomiasis transmission in the area and it was observed that the population of snails reestablished itself within three months of molluscicide application. The results obtained in this study do not encourage the continual use of niclosamide as the only method of control of schistosomiasis.

Influence of several plant extracts on the oviposition behaviour of Aedes fluviatilis (Lutz) (Diptera: Culicidae) in the laboratory

Whole, ethanolic, hexanic, lyophilized extracts of several plants and anacardic acid tested in respect of their influence on the oviposition behavior of Aedes fluviatilis (Lutz) at 100, 10 and 1 ppm concentrations. Extracts of Allium stivum, Jatropha curcas, Mikania schenkii, Poinciana regia and Spatodea campanulata had a repulsive effect (α=0.05) on females at 100 ppm, those of Anacardium occidentale, Bidens segetum and Caesalpinia peltophoroides were also repelent at 10 ppm. Extracts of Coriandrum sativum (100, 10 and 1 ppm), Chara Zeylanica (10 ppm), Cupressus sempervirens (10 ppm), Foeniculum vulgare (10 ppm) and Spatodea campanulata (1 ppm) were attractive to the females; 13 (52.0%) of the extracts tested, did not influence the oviposition behavior.

Atividade moluscicida da mistura de ácidos 6-n-alquil salicílicos (ácido anacárdico) e dos seus complexos com cobre (II) e chumbo (II)

The molluscicide activity of hexanic extract from Anacardium occidentale L. (cashew) nut shell, of copper (II) complex, of lead (II) complex and anacardic acid has been compared in the laboratory in an attempt to obtain better stability than anacardic acid. This was obtained from the hexanic extract of the cashew nut shell by precipitation with lead (II) hydroxide or cupric sulfate plus sodium hydroxide or (II) cupric hydroxide followed by treatment of lead (II) complex with a diluted solution of sulfuric acid. Ten products of the mixture obtained were tested on adults snails of Biomphalaria glabrata at 1 to 10 ppm. The most active products were copper (II) complex, obtained by cupric sulfate plus sodium hydroxide, and anacardic acid (sodium hydroxide) which presented activity at 4 ppm. The anacardic acids lead content was above the limits accepted by the United States standards.