Thesis (Ph. D.)--University of Michigan, 1928. / Cover title. "Reprinted from Papers of the Michigan Academy of Science, Arts and Letters, vol. XIII, 1930. Published 1931." "Literature cited": p. 597-599.

Cercariae of the digenean Plagiorchis noblei penetrate and kill a variety of aquatic larval dipterans. The present study determined whether these parasites can infect blackfly larvae, and established what biotic and abiotic factors affect parasite acquisition and the survival of infected hosts in the laboratory. Four species of blackfly larvae, Prosimulium mixtum, Simulium vittatum, S. decorum, and Stegopterna mutata, were exposed to cercariae in flowing water. Prevalence and intensity of infection of all species varied directly with exposure intensity and decreased with increasing water velocity, prevalence increased with larval size. Infection levels were higher for P. mixtum. The production of silk strands by the blackfly larvae and their persistence at low water velocities may facilitate parasite acquisition. Mortality among infected larvae of all species was three times that of controls. The data suggest that exposure to P. noblei cercariae adversely affected the survival of blackfly larvae.

No description available.

Thèse--Sc. nat.--Rennes, 1979. / Bibliogr. p. 247-268.

No description available.

No description available.

Th. 3e cycle--Entomol., méd. vét.--Paris 11--Orsay, 1980. N°: 2868.

No description available.

This research was designed to gain a better understanding of the oogenesis of the autogenous black-fly, Simulium vittatum and to compare it with studies on other Diptera. The autogenous character in S. vittatum showed only for the first gonadotropic cycle. Since the cytoblasts are first produced in the late larval period, the late larvae, early pupae, late pupae and adults of various ages were prepared separately for histological and histochemical examination. The adult female flies were fed only sugar and water. The changes in size, histology, and histochemistry of the oocyte, follicular cells and nurse-cells during oogenesis were described and the possible physiological role of these cells in oogenesis suggested. The amount and composition of larval fat-body remaining in females was compared with the stages of the oocyte development and the age of the flies. / Thesis / Master of Science (MS)

O objetivo desta Tese é realizar o levantamento taxonômico e avaliar a dinâmica populacional de Simuliidae em localidades sob influência do Aproveitamento Hidrelétrico de Peixe Angical, TO. Os simulídeos possuem abrangente distribuição geográfica, e os estágios imaturos utilizam ambientes lóticos como sítios de criação. Algumas espécies podem atuar como vetores de vírus, protozoários e helmintos, o que confere ao grupo importância médica e veterinária. O hábito hematofágico das fêmeas de simulídeos pode acarretar sérios prejuízos ao turismo; ocasiona baixa no rendimento escolar; e na agropecuária dificulta a execução do trabalho o que reduz a produtividade. Durante a construção de grandes empreendimentos ocorre em pouco tempo à introdução de contingente populacional com drástica transformação do meio. A intervenção do homem sobre os ecossistemas e o crescimento desordenado pode provocar desequilíbrio ecológico que propicia a proliferação de espécimes vetores com consequentes problemas médico sanitários. A maior parte dos trabalhos realizados com insetos vetores em áreas sob influência da construção de hidrelétricas se refere aos culicídeos. O estudo dos aspectos taxonômicos permitirá o levantamento da biodiversidade e o diferencial deste projeto está no estabelecimento da sazonalidade e dinâmica das populações de imaturos e adultos de simulídeos. As amostras foram obtidas em áreas de influência direta e indireta da UHE Peixe no rio Tocantins, em 12 pontos diferentes de coleta, nos municípios deJaú do Tocantins, Peixe, Palmeirópolis, Paranã e São Salvador do Tocantins. Foram realizadas bimestralmente de 2004 a 2007, um total de 24 campanhas para coleta em criadouros pré-selecionados, que acompanharam todas as fases de construção início das obras, formação do lago, funcionamento da Usina. OS dados abióticos foram aferidos, e os imaturos removidos do substrato manualmente por 10 minutos e posteriormente preparados para eclosão dos adultos. Parte do material foi identificado no Laboratório de Simulídeos e Oncocercose do Instituto Oswaldo Cruz, onde foram verificados novos registros específicos para a ocorrência de Simuliidae em Tocantins, além do assinalamento de espécies antropofílicas e/ou vetores de Onchocerca volvulus. Nas áreas usadas para a formação do lago houve desaparecimento de criadouros. O desmatamento ocorrido aliado ao vigor dos simulídeos que conseguem realizar voos de longas distâncias na procura de alimento ou locais adequados a oviposição devem ter contribuído para a dispersão de espécimes. Há relatos sobre a da ocorrência de oncocercose na área estudada, um foco foi demarcado na divisa de Goiás com Tocantins, municípios Paranã e Minaçu investigado a partir de um caso autóctone de oncocercose. Este estudo é relevante uma vez que o Brasil possui potencial hidroenergético e prevê a construção de inúmeras hidrelétricas nos próximos anos. É importante estudas as áreas impactadas, conhecer a sua biodiversidade e os aspectos bioecológicos de Simuliidae no país. / This project aims to carry out the taxonomic survey and population dynamics of Simuliidae in locations under the use influence of hydroelectric power station at Peixe Angical (Tocantins). Immature black-flies use lotic environments as rearing sites. Some species are vectors of viruses, protozoa or helminths, which assigns them medical as well as veterinary importance. The blood feeding habits of females affect rural life causing financial damages to tourism, declining of school performance and reducing of agricultural productivity. During the construction of large enterprises the need of hiring extra personnel drastically affects the environment. Human intervention on ecosystems as well as disorderly population growth can cause ecological imbalance added to significant vector proliferation causing health as well as sanitary problems. Deforestation and exploitation in the river beds also affect population of black-flies dynamics influencing their geographical distribution. In specialized literature, most of the work carried out in hydroelectric construction areas is referred to culicidae. Studies that mention black-flies in impacted areas by hydroelectric power stations in Brazil are restricted to taxonomic survey and brief comments on the formation of lakes with consequent disappearance of breeding sites in lotic environments. This research work is part of a larger project that studies the black-flies and their local associated entomological fauna, which will allow us to carry out its biodiversity surveillance. The differential of this project is to establish the seasonality and population dynamics of immature as well as adult black-flies. Samples were obtained in areas of direct and indirect influence of Peixe Hydroelectric power station in 12 different collecting sites in the municipalities of Peixe, Paranã, Palmeirópolis, Jaú and São Salvador do Tocantins. Were conducted bimonthly from 2004 to 2007, a total of 24 campaigns, which accompanied building phases: start of groundwork, lake formation and operation of the plant. All abiotic data were registered and immature black-flies removed from the substrate for 10 minutes and prepared for the outbreaking of adults. Part of the material has been identified at the Simuliidae and Onchocerciasis laboratory at Oswaldo Cruz Institute, where new records of specific occurrence of Simuliidae in Tocantins have been registered, as well as anthropophilic species and / or vectors of Onchocerca volvulus. Mansonella ozzardi of vector species were not collected in the study area. It is expected that the prevalence is higher in the rainy months of the year. In areas where there was a lake formation there was loss of habitats. Black-flies can fly long distances in search of food or oviposition sites and that fact, coupled with deforestation may lead to the dispersal of species. There is a report on the occurrence of an autochthonous case of onchocerciasis in Paranã and Minaçu, municipality of Goiás and boarding area of the studied sites. This study is relevant to knowledge of biodiversity and bioecological aspects of Simuliidae in Brazil.