RESUMO

Tabanidae are considered a nuisance to humans, wild animals, and livestock due to their painful, annoying, and insistent biting. Tabanids transmit some pathogens and parasites biologically and mechanically. In humans, there are relatively few pathogens transmitted regularly. Still, tabanids serve as vectors of a number of disease agents of animals, including viruses, bacteria, protozoans, and nematodes. They are more abundant in tropical and humid regions, and their seasonal patterns are affected by habitat changes such as deforestation and fragmentation. Here, we analyze the tabanid fauna in Monte Negro, a central municipality of Rondônia, Brazil, comparing abundance, richness, and diversity in forest and pasture habitats. Traps were set for 5 days a month for 12 consecutive months. We also examined how abiotic factors (humidity, temperature, and rainfall) affected the abundance, diversity, and richness and the effectiveness of Malaise and Nzi traps as sample methods. The influence of climatic variables on the richness and abundance of the species was tested using generalized linear models, and we used non-parametric dimensional scaling (nMDS) for analysis of species composition and diversity in different traps and environments. We collect 1032 specimens of 25 species. The most abundant species were Tabanus antarcticus, Dichelacera tetradelta, Tabanus mucronatus, and Leucotabanus albovarius. Forest habitats had the highest number of tabanids, followed by pasture and the anthropized area, and there was no significant difference regarding the effectiveness of the Malaise and Nzi traps. The study provides new information on the distribution and ecology of tabanids in Brazil.

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RESUMO

Tabanidae (Diptera), popularly known as horse flies, is an important vector group. This is the first study to ascertain the abundance and diversity of horse flies in horses at the cerrado biome of the state of Tocantins, Brazil. Collecting took place in typical Cerrado, and sampling occurred in the dry and rainy seasons. The horseflies were collected from horses using an entomological net. A total of 249 individuals were collected and spread over 25 species. The prevalent species were Stypommisa aripuana (25.8%) and Catachlorops rufescens (6.4%), in the dry period, and Fidena lissorhina (22.5%), Tabanus occidentalis var. dorsovittatus (10%) and Poeciloderas quadripunctatus (6.4%), in the rainy season. The results suggest that tabanids attack horses throughout the dry and rainy seasons, posing a constant threat to their health in the Cerrado of Tocantins.

Assuntos

RESUMO

Horse fly females (Diptera, Tabanidae) are hematophagous and can vector pathogens that affect livestock. Complexes of cryptic species are common in Tabanidae, as exemplified by some species of Tabanus, including Tabanus triangulum and Tabanus occidentalis, both prevalent in the Southern region of Brazil. In this study, geometric morphometrics were employed to ascertain the wing venation in species identification. It was demonstrated that this tool effectively differentiates T. triangulum from T. occidentalis in the coastal plain of Rio Grande do Sul state, situated within the Pampa biome. The results indicate that T. triangulum and T. occidentalis occupy distinct regions of the morphological space, allowing their precise identification through geometric morphometrics, which is fast, affordable, and easy to implement.

Assuntos

RESUMO

Abstract Tabanidae (Diptera), popularly known as horse flies, is an important vector group. This is the first study to ascertain the abundance and diversity of horse flies in horses at the cerrado biome of the state of Tocantins, Brazil. Collecting took place in typical Cerrado, and sampling occurred in the dry and rainy seasons. The horseflies were collected from horses using an entomological net. A total of 249 individuals were collected and spread over 25 species. The prevalent species were Stypommisa aripuana (25.8%) and Catachlorops rufescens (6.4%), in the dry period, and Fidena lissorhina (22.5%), Tabanus occidentalis var. dorsovittatus (10%) and Poeciloderas quadripunctatus (6.4%), in the rainy season. The results suggest that tabanids attack horses throughout the dry and rainy seasons, posing a constant threat to their health in the Cerrado of Tocantins.

Resumo Os tabanídeos, popularmente conhecidos como mutucas, representam um importante grupo de vetores. Este é o primeiro estudo a verificar a abundância e diversidade de mutucas em cavalos, no bioma cerrado do estado do Tocantins, Brasil. As coletas ocorreram em ambiente típico de Cerrado e as amostragens nos períodos seco e chuvoso. Mutucas foram coletadas de cavalos por meio de rede entomológica. Um total de 249 indivíduos foi coletado, representando 25 espécies. As espécies mais abundantes foram Stypommisa aripuana (25,8%) e Catachlorops rufescens (6,4%), no período seco, e Fidena lissorhina (22,5%), Tabanus occidentalis var. dorsovittatus (10%) e Poeciloderas quadripunctatus (6,4%), no período chuvoso. Os resultados sugerem que os tabanídeos atacam equinos ao longo das estações seca e chuvosa, constituindo uma ameaça constante à sua saúde no Cerrado do Tocantins.

RESUMO

Abstract Horse fly females (Diptera, Tabanidae) are hematophagous and can vector pathogens that affect livestock. Complexes of cryptic species are common in Tabanidae, as exemplified by some species of Tabanus, including Tabanus triangulum and Tabanus occidentalis, both prevalent in the Southern region of Brazil. In this study, geometric morphometrics were employed to ascertain the wing venation in species identification. It was demonstrated that this tool effectively differentiates T. triangulum from T. occidentalis in the coastal plain of Rio Grande do Sul state, situated within the Pampa biome. The results indicate that T. triangulum and T. occidentalis occupy distinct regions of the morphological space, allowing their precise identification through geometric morphometrics, which is fast, affordable, and easy to implement.

Resumo Fêmeas de mutucas (Diptera, Tabanidae) são hematófagas e podem ser vetores de patógenos que afetam animais de criação. Complexos de espécies crípticas são comuns em Tabanidae, como exemplificado por algumas espécies de Tabanus, incluindo Tabanus triangulum e Tabanus occidentalis, ambas prevalentes na região Sul do Brasil. Neste estudo foi utilizada morfometria geométrica para avaliar a venação das asas na identificação de espécies. Foi demonstrada que essa ferramenta diferencia, efetivamente, T. triangulum de T. occidentalis na Planície Costeira do Rio Grande do Sul, situada no bioma Pampa. Os resultados indicam que T. triangulum e T. occidentalis ocupam regiões distintas do espaço morfológico, permitindo sua identificação precisa por meio da morfometria geométrica, a qual é rápida, acessível e fácil de implementar.

RESUMO

Tabanidae is one of the most diverse families of hematophagous dipterans. Tabanids, in general, are mechanical vectors of some pathogens. Given the vector importance and the lack of knowledge of the tabanid fauna in horses in Amazon Forest fragments of the state of Rondônia, this work aimed to determine the season that the different species of horse flies prefer to carryout hematophagy on horses and verify whether the horse fly community remains the same throughout the year. The sampling areas for tabanid captures were in the municipality of Monte Negro, Western Amazon, Brazil. Four new occurrences were recorded for the state of Rondônia: Stenotabanus albilinearis, Tabanus fuscofasciatus, T. macquarti and T. restrepoensis, which increases the number of species for the state to 109. The horse flies were most frequently collected on the hind leg (43.15%) and front leg (31.11%), followed by the belly (7.41%) and the ear (5.18%). In the other anatomical regions, the collection frequency was 13.15% of the remaining individuals.

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ABSTRACT Larvae of Hydrotaea species are facultative predators of larvae of other fly species on poultry farms, chicken feces, pig, and decaying carcasses. The Neotropical species H. albuquerquei occurs together with M. domestica in these environments and might be useful in the biological control of the latter. To verify the predatory capacity of H. albuquerquei larvae on the larvae of M. domestica, we varied the size of the larvae and the densities of the predators and prey under controlled laboratory conditions. Adults were collected from a poultry farm for the experiment, and the larvae they produced were reared in the laboratory. The second and third instar larvae of H. albuquerquei, when at higher densities, suppressed populations of house fly larvae when the latter were smaller than the former. This means that the functional response increases gradually with an increase in prey population density and predator size. In these conditions, one H. albuquerquei larva consumes up to 29 M. domestica larvae at high prey densities and could reduce 100% of the house fly population under a 50% prey density. This study confirmed a pattern previously observed in other predatory larvae and our results have implications for the biological control and integrated pest management programs of M. domestica in poultry and swine farms.

RESUMO

Several studies have described the effects of human tumor necrosis factor alpha (hTNF-α) on Schistosoma mansoni. hTNF-α affects the worm's development, metabolism, egg-laying, gene expression and protein phosphorylation. The available data on the influence of hTNF-α on egg-laying in S. mansoni are controversial, but understanding the mechanism of egg-laying regulation in this species is essential in combating schistosomiasis. We characterized the effects of in vitro treatment of S. mansoni adult worms with different doses of hTNF-α (5, 20 and 40 ng/ml) for 5 days. We explored the effects on egg-laying rate, glucose levels, ATP metabolism, and messenger RNA (mRNA) expression levels of lactate dehydrogenase, glucose transporters and the parasite gene which acts as an hTNF-α receptor, SmTNFR. hTNF-α influenced egg-laying in a time- and dose-dependent manner: at a dose of 40 ng/ml, egg-laying increased on day 2 and decreased on days 3 and 4; at 20 ng/ml, egg-laying decreased on day 3; while at 5 ng/ml, egg-laying decreased on day 4. The total number of eggs produced was not affected by the different treatments, but the egg-laying dynamics were: the median egg-laying time decreased significantly with treatment, and egg developmental stages and size were also affected. At 5 and 20 ng/ml hTNF-α, lactate production diminished on day 3 up to day 5, while glucose uptake increased on day 5. At 40 ng/ml, glucose uptake diminished on day 1 up to day 3, while ATP accumulation was detected on day 5. No significant changes in mRNA expression were detected in any of the treatments. We found that crosstalk involving hTNF-α and parasite signaling plays a role in the fine-scale regulation of the worm's metabolism and physiology, and points to new strategies for disease control.

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