Resultados de combate ao "ácaro rajado" Tetranychus urticae koch, 1836, em algodoeiro

Devido aos grandes prejuízos causados pelo "ácaro rajado" 'Tetranychus urticaKoch, 1836, ã cotonicu1tura brasileira , foi realizado o presente trabalho. Vários produtos foram experimentados ,totalizando oito tratamentos: clofentezina (25O e 750 g/ha com uma aplicação cada e 25O g/ha com duas aplicações), fempropatrina (75 e 150 g/ha), binapacril (800 g/ha), cipermetrina + profenofós (50 g + 500 g/ha) e testemunha. A análise dos resultados mostra que as três dosagens de clofentezina constituíram os únicos tratamentos viáveis desta seleção, apresentando ótimos resultados contra o ácaro e efeito residual relativamente longo.

Eficiência no combate ao ácaro da falsa ferrugem dos citros Phyllocoptruta Oleivora (ASHMEAD, 1879)

A fim de combater experimentalmente o ácaro da falsa ferrugem, de grande destaque na cultura dos citros, estabeleceu-se num campo de laranjeiras adultas um ensaio com os seguintes tratamentos e quantidades de ingredientes ativos por hectare: A - testemunha; B - bromopropilato (567,5g); C - fempropatrina (340,5g); D - clofentezina (567,5g); E ometoato 1397,0g); F- manebe (1396,8g) (Tabela 1). Cada laranjeira recebeu em cobertura seis litros de calda aplicada com pulverizador motorizado (atomizador costal). Realizaram-se onze avaliações: a inicial (dois dias antes da pulverização) e dez outras pós-pulverização (05, 11, 19, 32, 46, 60, 73, 89, 107, 117 dias depois da aplicação) (Tabela 2). Até os 46dias os tratamentos apresentavam resultados quase bons a ótimos; a partir desse prazo, destacaram-se apenas o bromopropilato e a clofentezina (Tabelas 3 e 4).

Pulverização de novos acaricidas no combate ao ácaro da leprose Brevipalpus phoenicis (GEIJSKES, 1939) (Acari: Tenuipalpidae) em citros

O ácaro da leprose é, segundo alguns autores, o vetor responsável pela transmissão da leprose, doença possivelmente causada por um vírus. Este trabalho foi realizado com o objetivo de combate químico ao ácaro, que nos últimos anos está se tornando mais importante. Os tratamentos eram seis, cada um com quatro repetições, mas os produtos eram três. Cada laranjeira recebeu 3,33 litros de calda. Todos os defensivos utilizados conduziram a excelentes resultados até os 89 dias após a pulverização, ocasião em que os trabalhos foram encerrados.

Oviposition behaviour of Gryon gallardoi (Hymenoptera, Scelionidae) on eggs of different ages of Spartocera dentiventris (Hemiptera, Coreidae)

The oviposition behaviour of Gryon gallardoi (Brèthes, 1914) on eggs of Spartocera dentiventris Mendonça Jr. (Berg, 1884) of different ages (2, 3, 4, 5, 6, 7, 8 and 12 days) was investigated. Groups of 12 eggs of each age were exposed to single females of G. gallardoi, and the oviposition behaviour was recorded under a stereomicroscope for two hours. Ten replicates were used for each age. In order to identify the moment the parasitoid egg was released inside the host, 1-day old eggs of S. dentiventris were exposed to G. gallardoi females, and the oviposition was interrupted at intervals of 20, 40, 60, 80, 100, 120, 140 and 160s after ovipositor insertion had initiated. Five behavioural steps were recorded: drumming, ovipositor insertion, marking, walking and resting. The average drumming and ovipositor insertion times increased with the host age (P<0.01). Ovipositor insertion usually occurred next to the longitudinal extremities of the host eggs. Marking took on average 19.5 ± 0.7s, and as walking and resting, was not affected by host age. Self-parasitism behaviour was observed in only 13.8 ± 2.3% of the eggs, being more evident with increasing patch depletion (reduction in non-parasitized eggs in the egg group, P<0.01), again with no variation due to changes in host egg age. For all ages tested, self-parasitized host eggs were less frequently contacted and accepted than non-parasitized ones (P<0.01). The parasitoid egg was released 137.0 ± 3.7s after ovipositor insertion. Spartocera dentiventris egg condition can lead to parasitoid behavioural changes, especially during the process of host choice and discrimination.

Caracterização do grupo Edessa rufomarginata e descrição de sete novas espécies (Heteroptera, Pentatomidae, Edessinae)

Neste trabalho é proposto o grupo Edessa rufomarginata, que inclui E. rufomarginata (De Geer, 1773), E. marginalis (Dallas, 1851), E. albomarginata (Stål, 1855), E. abdominalis Erichson, 1848, E. corallipes Erichson, 1848, E. aulacosterna Stål, 1872, E. ovalis Stål, 1872 e E. nigropunctata Berg, 1884. São descritas sete novas espécies pertencentes ao grupo, seis do Brasil e uma da Argentina: E. brasiliensis sp. nov., E. castaneolineata sp. nov., E. cerradensis sp. nov., E. chapadensis sp. nov., E. luteovenulata sp. nov., E. rufodorsata sp. nov. (Argentina) e E. virididorsata sp. nov. As espécies deste grupo ocorrem na Venezuela, Suriname, Guiana, Brasil, Paraguai e Argentina.

Abundância e sazonalidade de cigarrinhas (Hemiptera, Cicadellidae, Cicadellinae) em vegetação herbácea de pomar de laranja doce, no município de Montenegro, Estado do Rio Grande do Sul, Brasil

O presente estudo teve por objetivo conhecer a flutuação populacional e a constância de cicadelíneos presentes na vegetação herbácea de um pomar de laranja doce (Citrus sinensis (L.) Osbeck), variedade Valência, em Montenegro, RS. O levantamento foi realizado com a metodologia da rede-de-varredura, tendo início em fevereiro de 2001 e finalizando-se em janeiro de 2002. Mensalmente foram coletadas dez amostras, sendo cada uma destas composta por 50 golpes de rede em movimento de avanço sobre a vegetação herbácea e cultura intercalar nas entrelinhas do pomar (n = 500 golpes/ocasião de coleta). No total foram coletados 928 cicadelíneos, pertencentes a nove espécies: Bucephalogonia xanthophis (Berg, 1879), Diedrocephala variegata (Fabricius, 1775), Hortensia similis (Walker, 1851), Macugonalia leucomelas (Walker, 1851), Parathona gratiosa (Blanchard, 1840), Plesiommata corniculata Young, 1977, Sibovia sagata (Signoret, 1854), Sonesimia grossa (Signoret, 1854) e Tapajosa rubromarginata (Signoret, 1855). O período de maior abundância da comunidade de cicadelíneos foi durante a primavera e o verão. Hortensia similis e M. leucomelas foram as únicas espécies consideradas constantes durante o levantamento. A menor abundância dos cicadelíneos em abril e dezembro provavelmente deve-se a efeitos causados por fatores abióticos (pluviosidade) e aqueles relativos à estrutura da vegetação (altura das plantas) sobre a comunidade.

The influence of prior experience with artificial fruits on the ovipositioning behavior of Anastrepha fraterculus (Diptera, Tephritidae)

The South American fruit fly, Anastrepha fraterculus (Wiedemann, 1830) (Diptera, Tephritidae), is a leading pest of Brazilian fruit crops. This study evaluated how prior experience with artificial fruits containing peach and/or guabiroba pulp influenced the ovipositing behavior of A. fraterculus. Insects 15-21 days old were exposed to four treatments: 1) experience with guabiroba, Campomanesia xanthocarpa O. Berg (Myrtaceae); 2) experience with peach, Prunus persica (L.) Batsch (Chimarrita cultivar; Rosaceae); 3) experience with both fruits; and 4) no experience (naive). Naive females and females experienced with guabiroba pulp and with both fruits (peach and guabiroba) oviposited and showed dragging and puncturing behavior on substrates containing guabiroba, but females that were only exposed to peach pulp did not show a preference for any substrate. The study shows that prior experience with substrate influences ovipositing behavior in A. fraterculus.

Enteric parasites and HIV infection: occurrence in AIDS patients in Rio de Janeiro, Brazil

The occurrence of intestinal parasites, its relation with the transmission mechanism of HIV, and the clinical state of the AIDS patients, were analyzed in 99 Group IV patients (CDC, 1986), treated at "Hospital Universitário Pedro Ernesto" (HUPE), between 1986 and 1988. The group consisted of 79 (79.8%) patients whose HIV transmission mechanism took place through sexual contact and of 16 (20.2%) who were infected through blood. Feces samples from each patient were examined by four distincts methods (Faust et al, Kato-Katz, Baermann-Moraes and Baxby et al.). The moste occuring parasites were: Cryptosporidium sp., Entamoeba coli and Endolimax nana (18.2%), Strongyloides stercoralis and Giardia lambia (15.2%). E. histolytica and/or E. hartmanni (13.1%), Ascaris lumbricoides (11.1%) and Isospora belli (10.1%). Furthermore, 74.7% of the patients carried at least one species. Intestinal parasites were found in 78.5% of the patients who acquired the HIV through sexual intercourse and in 56,3% of those infected by blood contamination. The difference, was not statistically significant (p > 0.05). In the group under study, the increase of the occurrence of parasitc infections does not seem to depend on the acquisiton of HIV through sexual contact. It appears that in developing countries, the dependancy is more related to the classic mechanisms of parasites transmission and its endemicity.

Seasonal distribution of a relatively rare and a relatively common species of Thecomyia at Belém, Pará, Brazil (Diptera: Sciomyzidae)

O gênero neotropical Thecomyia (Sciomyzidae) consiste de quatro espécies descritas e onze ainda não descritas (Steyskal & Knutson em preparação), sendo a maioria não muito comum. As espécies são muito próximas e grande número delas somente pode ser separado com base na genitália do macho. Somente é conhecida a biologia e uma espécie, T. limbata (Wiedermann), que, preferentemente, preda moluscos aquáticos (Abercrombie & Berg, 1975). A análise de registros de coletas de espécies relativamente raras e relativamente comuns de Thecomyia (172 especimens do Museu Goeldi coletados em Mocambo, Belém, Pará, Brasil) proporcionam informações sobre a distribuição sazonal de espécies tropicais e sua relativa abundância. Deste material 160 especimens pertencem à T. longicornis Perty e 12 à Thecomyia sp. n. A primeira foi registrada durante todos os meses do ano, mas a espécie nova somente durante junho e dezembro, sugerindo esta última uma população de adultos anual bimodal.

Cross-sectional and evolutive studies of schistosomiasis mansoni in untreated and mass treated endemic areas in the southeast and northeast of Brazil

Cross-sectional and evolutive studies on schistosomiasis mansoni were carried out before and after mass treatment in the endemic areas of Capitao Andrade and Padre Paraíso, state of Minas Gerais, Riachuelo, state of Sergipe, Alhandra, state of Paraíba, and Aliança, Alegre and Coroatá, lowland of the state of Maranhao, Brazil, in the last eighteen years. The studies included clinical and fecal examination by the Kato-Katz quantitative technique, skin testfor Schistosoma mansoni infection, evaluation of man-water contact and other epidemiological investigations such as infection rate and dynamic of the snail population. Results showed: (1) Higher prevalence of S. mansoni infection, greater egg load elimination and higher and earlier morbidity of the chronic froms of the disease in the southeast areas of Capitao Andrade and Padre Paraíso; (2) The incidence of hepatosplenic form is higher in some family clusters, in whites and mullattos in all the endemic areas but develop earlier in the southeast; (3) The prevalence and morbidity of schistosomiasis are decreasing both in the mass treated northeast and in the untreated southeast areas; (4) The mass treatment reduces rapidily the prevalence of the infection and the morbidity of the disease but can not control it because of the frequent reinfections due to the intensity of man-water contact.

New approaches for the control and eradication of schistosomiasis in Venezuela

Schistosomiasis in Americawith the exception of Brazil, behaves as a chronic mild disease with few clinical manifestations due to low parasite burden. These features restrict the clinical and parasitological diagnosis. The most commonly used stool examination method, Kato-Katz, becomes intensitive when the majority of individuals excrete less than 100 eggs/g of feces. In view that antigen-detecting techniques have not been able to reveal light infections, the antibody detecting assays remain as a very valuable diagnostic tool for epidemiological surveillance. The Venezuelan Schistosomiasis Research group (CECOICE) has designed a mass chemotherapy strategy based on sero-diagnosis. Since blood sampling is one of the important limitating factors for large seroepidemiological trials we developed a simple capillary technique that sucessfully overcomed most of the limitations of blood drawing. In this sense, ELISA seems to be the most adecuate test for epidemiological studies. Soluble egg Schistosoma mansoni antigen (SEA) has been largely used in Venezuela. The sensitivity ELISA-SEA in our hands is 90% moreover its specific reach 92% when populations from non-endemic areas but heavily infected with other intestinal parasites are analyzed. The Schistosomiasis Control Program is currently carrying out the surveillance of endemic areas using ELISA-SEA as the first screening method, followed by the Circumoval Precipitin test for validation assay. The results with these two serological techniques allowed us to defined the criteria of chemotherapy in populations of the endemic areas. On the search of better diagnostic technique, Alkaline Phosphatase Immunoenzyme Assay (APIA) is being evaluated in field surveys.

Controle da esquistossomose mansônica em área de baixa transmissao

The schistosomiasis is transmitted by Biomphalaria tenagophila in our study area (Pedro de Toledo, Sao Paulo, Brazil). From 1980 to 1990 epidemiological surveys in a population of 4.000 inhabitants, has shown that: prevalence Kato-Katz (KKT), immunofluorescence (FT) and intradermal (IDT) techniques were 22.8%, 55.5% and 51.8% respectively; intensity of infection was low, 58.5 eggs per gram of faeces (epg); there were no symptomatic cases; prevalences were higher in mates, children and rural zone; index of potential contamination was 57.5% in the age group 5 to 20 years; 2/3 of patients were autochtonous; cases were no-randomly aggregated; transmission was focal and only 0.4% of snails were infected; water contacts through recreation showed the most important odds ratio; knowledge, attitudes and practices were satisfatory. From the epidemiological control findings a control programme was carried out; yearly faeces exams, chemotherapy, molluscocide, health education and sanitation. Thus, the prevalence decreased sharply to 3.3% and intensity of infection to 30.3 epg; the incidence rates ranged between 0.4% and 2.5% annualy; the sanitation became better and the youngsters were the main target in prophylaxis. To improve control, immunodiagnosis has to be conducted and the involvment of the population should be increase. However, we cannot forget that re-infection and the involvment of the population should be increase. However, we cannot forget that re-infection, therapeutic failure, etc, could play a major role in the maintnance this residual prevalence.

Parasitological diagnosis of schistosomiasis mansoni: fecal examination and rectal biopsy

Even with all progress in the search of sensitive and methods for the immunological diagnosis of schistosomiasis, the microscopic detection of eggs of the parasite in the stool still remains the most widely used tool for the actual diagnosis of active infection. Among the coproscopic methods, Kato's technic modified by Katz et al (Kato/Katz) has the advantages of higher sensitivity, the possibility of egg quantification, its low operational cost and its feasibility in areas with minimal infra-structure. The oorgram of the rectal mucosa is valuable in initial clinical trials of schistosomicides, when it is needed to observe egg morphology in tissue. It could be an alternative method for individual diagnosis, being more sensitive than a single stool exam in low intensity infection. However, the increased sensitivity of a higher number of fecal exams makes that invasiveprocedure unnecessary. In the assessment of cure of schistosomiasis, Kato/Katz method (three fecal samples in one, three and six months after treatment) and the rectal biopsy four months after treatment, are equally reliable.

Esquistossomose mansoni: tratamento medicamentoso

It is the specific treatment of mansoni schistosomiasis that aims to act directed on the parasite, through chemotherapy. Constitutes fundamental indication to the treatment of schistosomiasis active forms, that is, these determined by the presence of living eggs in the feces or in material from rectal biopsy, since eventual contra indications are respected. Two are the medicaments actually used: oxamniquine, used in the single dosage of 15mg/kg, V.O. for adults and 20mg/kg V.O. for children divided in two doses, offers a percentage of 30 to 40% of cures, evaluated by quantitative "oogram" and prazinquantel, in the single dose of 60 mg/kg V.O., presents a cure index of 30% however in seriate doses, of 60mg/kg during 3 days or 30mg/kg, 6 days, cure percentage is elevated to 95% evaluated by oogram. The evaluation of the treatment by quantitative or qualitative examination methods does not show the same sensibility. The percentage of cure according to feces examination, the quantitative of Kato-Katz or the qualitative (sedimentation), showed indexes from 90 to 100% for either one of the drugs, even in single dose, which evidences the difference of methodology of therapeutic evaluation. Tolorance to both medicaments is from good to regular, with collateral effects in 30 to 40% of the patients.

Schistosomiasis mansoni in the region of the Triângulo Mineiro, State of Minas Gerais, Brazil

In order to reevaluate the possible presence of schistosomiasis mansoni in the Triângulo Mineiro, one of the areas of the State of Minas Gerais where this parasite is not commonly found, malacological survey and fecal examinations were undertaken in the region between October 1990 and June 1992. A sample of 7,032 1st grade school children from 29 counties had their feces examined using the Kato-Katz method. Amongst the children examined, two from Planura and one from each countie of Capinópolis, Conceição das Alagoas, Uberaba, Uberlândia, Prata and Gurinhatã were positive for Schistosoma mansoni. None of the children were identified as being autoctonous cases. In the malacological survey, 5,406 planorbid snails were examined. The specimens were identified morphologically and examined for S. mansoni by squashing between glass plates. The species were identified as Biomphalaria tenagophila in three counties, as B. straminea in ten and B. intermedia in 16. No snails were found in eight other counties studies. The snails were found to be negative for S. mansoni. The presence of intermediate hosts for S. mansoni, associated with parasitized individuals emphasizes the necessity of epidemiological surveillance for schistosomiasis in the region of Triângulo in the State of Minas Gerais.