Horse Flies (Diptera: Tabanidae) in Mangrove Forests and Estuarine Floodplains on Marajó Island, Brazil.

Tabanids constitute an important group of hematophagous insects that can transmit zoonoses, but with studies on the ecological distribution of species still neglected in the Amazon. We evaluated the role of mangrove forests and estuarine floodplains located inside and outside a conservation unit (UC) on the coast of Marajó Island, Amazon River estuary, on the diversity and distribution of tabanids. Specifically, we studied whether the community of mangrove and estuarine floodplain tabanids located inside and outside the UC differ in abundance, richness, and species composition. We collected tabanids using a Malaise trap at 40 sampling points, resulting in 637 specimens distributed in 13 species and one morphotype, representing approximately 37% of the tabanid fauna ever recorded for the Marajó Island. There was no significant difference in the richness and composition of tabanids between the phytophysiognomies, but the abundance was significantly different, with greater abundance in the mangrove. The areas inside and around the UC had an influence on the tabanids, with the areas inside the UC having the highest number of specimens and species, also influencing the species composition. Two species are new records for the Marajó Island, bringing the number of species recorded to 38. Our results suggest that, along the Amazonian coast, mangroves and estuarine floodplains maintain part of the diversity of tabanids known for the Brazilian Amazon. Our data also indicate that the region's UC provides potentially important habitats for the maintenance of local tabanid populations.

First records of two genera and thirteen species of Tabanidae (Diptera) from Honduras.

This works presents information on the diversity of the Tabanidae of Honduras as a product of the examination of 386 specimens and a literature review. Thirteen species and two genera (Bolbodimyia and Dasychela) are recorded from the country for the first time. Eighty-five species distributed in 22 genera, five tribes, and three subfamilies are now known from Honduras. A key to the subfamilies, tribes, and genera of the known Honduran species is also included. All new records are mapped and illustrated to aid in the identification of the species.

Shared species of crocodilian trypanosomes carried by tabanid flies in Africa and South America, including the description of a new species from caimans, Trypanosoma kaiowa n. sp.

BACKGROUND: The genus Trypanosoma Gruby, 1843 is constituted by terrestrial and aquatic phylogenetic lineages both harboring understudied trypanosomes from reptiles including an increasing diversity of crocodilian trypanosomes. Trypanosoma clandestinus Teixeira & Camargo, 2016 of the aquatic lineage is transmitted by leeches to caimans. Trypanosoma grayi Novy, 1906 of the terrestrial lineage is transmitted by tsetse flies to crocodiles in Africa, but the vectors of Neotropical caiman trypanosomes nested in this lineage remain unknown. RESULTS: Our phylogenetic analyses uncovered crocodilian trypanosomes in tabanids from South America and Africa, and trypanosomes other than T. grayi in tsetse flies. All trypanosomes found in tabanids clustered in the crocodilian clade (terrestrial lineage) forming six clades: Grayi (African trypanosomes from crocodiles and tsetse flies); Ralphi (trypanosomes from caimans, African and Brazilian tabanids and tsetse flies); Terena (caimans); Cay03 (caimans and Brazilian tabanids); and two new clades, Tab01 (Brazilian tabanid and tsetse flies) and Kaiowa. The clade Kaiowa comprises Trypanosoma kaiowa n. sp. and trypanosomes from African and Brazilian tabanids, caimans, tsetse flies and the African dwarf crocodile. Trypanosoma kaiowa n. sp. heavily colonises tabanid guts and differs remarkably in morphology from other caiman trypanosomes. This species multiplied predominantly as promastigotes on log-phase cultures showing scarce epimastigotes and exhibited very long flagellates in old cultures. Analyses of growth behavior revealed that insect cells allow the intracellular development of Trypanosoma kaiowa n. sp. CONCLUSIONS: Prior to this description of Trypanosoma kaiowa n. sp., no crocodilian trypanosome parasitic in tabanid flies had been cultured, morphologically examined by light, scanning and transmission microscopy, and phylogenetically compared with other crocodilian trypanosomes. Additionally, trypanosomes thought to be restricted to caimans were identified in Brazilian and African tabanids, tsetse flies and the dwarf crocodile. Similar repertoires of trypanosomes found in South American caimans, African crocodiles and tabanids from both continents support the recent diversification of these transcontinental trypanosomes. Our findings are consistent with trypanosome host-switching likely mediated by tabanid flies between caimans and transoceanic migrant crocodiles co-inhabiting South American wetlands at the Miocene.

Shared species of crocodilian trypanosomes carried by tabanid flies in Africa and South America, including the description of a new species from caimans, Trypanosoma kaiowa n. sp.

Background The genus Trypanosoma Gruby, 1843 is constituted by terrestrial and aquatic phylogenetic lineages both harboring understudied trypanosomes from reptiles including an increasing diversity of crocodilian trypanosomes. Trypanosoma clandestinus Teixeira & Camargo, 2016 of the aquatic lineage is transmitted by leeches to caimans. Trypanosoma grayi Novy, 1906 of the terrestrial lineage is transmitted by tsetse flies to crocodiles in Africa, but the vectors of Neotropical caiman trypanosomes nested in this lineage remain unknown. Results Our phylogenetic analyses uncovered crocodilian trypanosomes in tabanids from South America and Africa, and trypanosomes other than T. grayi in tsetse flies. All trypanosomes found in tabanids clustered in the crocodilian clade (terrestrial lineage) forming six clades: Grayi (African trypanosomes from crocodiles and tsetse flies); Ralphi (trypanosomes from caimans, African and Brazilian tabanids and tsetse flies); Terena (caimans); Cay03 (caimans and Brazilian tabanids); and two new clades, Tab01 (Brazilian tabanid and tsetse flies) and Kaiowa. The clade Kaiowa comprises Trypanosoma kaiowa n. sp. and trypanosomes from African and Brazilian tabanids, caimans, tsetse flies and the African dwarf crocodile. Trypanosoma kaiowa n. sp. heavily colonises tabanid guts and differs remarkably in morphology from other caiman trypanosomes. This species multiplied predominantly as promastigotes on log-phase cultures showing scarce epimastigotes and exhibited very long flagellates in old cultures. Analyses of growth behavior revealed that insect cells allow the intracellular development of Trypanosoma kaiowa n. sp. Conclusions Prior to this description of Trypanosoma kaiowa n. sp., no crocodilian trypanosome parasitic in tabanid flies had been cultured, morphologically examined by light, scanning and transmission microscopy, and phylogenetically compared with other crocodilian trypanosomes. Additionally, trypanosomes thought to be restricted to caimans were identified in Brazilian and African tabanids, tsetse flies and the dwarf crocodile. Similar repertoires of trypanosomes found in South American caimans, African crocodiles and tabanids from both continents support the recent diversification of these transcontinental trypanosomes. Our findings are consistent with trypanosome host-switching likely mediated by tabanid flies between caimans and transoceanic migrant crocodiles co-inhabiting South American wetlands at the Miocene.

Description of Muscotabanus gen. nov. and Muscotabanus rafaeli sp. nov. (Diptera: Tabanidae: Diachlorini) from Amazon Basin, Brazil

A new genus of Tabanidae mimetic of flies is described: Muscotabanus new genus, Muscotabanus rafaeli new species, based on 12 females collected in the state of Amazonas, Brazil. It is presented a discussion for separating the new genus from Diachlorini species which resemblance with sarcophagids flies. It is characterised by striped thorax, banded abdomen, long slender palpus subequal antenna length, labella predominantly membranous, except for a narrow sclerotised plate, basicosta bare, wing hyaline and stigma brown.

Trypanosoma vivax infection dynamics in a cattle herd maintained in a transition area between Pantanal lowlands and highlands of Mato Grosso do Sul, Brazil

Trypanosoma vivax outbreaks in beef cattle in the Pantanal region of Mato Grosso do Sul state, Brazil, causes relevant economical impact due to weight loss, abortion and mortality. Cattle moved from the Pantanal to adjacent areas of this ecosystem for breeding and fattening is a common feature. Therefore an epidemiological study on breeding cows in the transition area between Pantanal lowland and adjacent highlands of Mato Grosso do Sul was performed to determine the T. vivax infection dynamics and outbreak risk. Three experimental groups were formed: Group 1 consisted of cows parasitologically negative by the Woo test and in the enzyme-linked immunosorbent assay for T. vivax antibody detection (Tv-ELISA-Ab); Group 2 parasitologically negative and positive in the Tv-ELISA-Ab; and in Group 3 cows were parasitologically positive and with positive reactions in the Tv-ELISA-Ab. During 24 months, the cows' dislodgment between the above established groups was monitored by Woo test and Tv-ELISA-Ab exams. The tabanid population was also monitored and the highest number occurred during the rainy season. Although parasitemias were detected only in the first four samplings of the experimental period, the cows could be considered as trypanotolerant, because no clinical signs were observed. Despite the higher T. vivax incidence during the dry season, no disease symptoms were seen. Even though T. vivax epidemiological situation in the herd was characterized as endemic with seasonal variation, the probability of outbreaks was null within the conditions of the study.

Surtos de Trypanosoma vivax em bovinos de corte do Pantanal foram responsáveis por relevante impacto econômico, devido a perda de peso, abortos e mortalidade. Um manejo comum é o deslocamento de bovinos do Pantanal baixo para áreas adjacentes desse ecosistema para reprodução e engorda. Por essa razão, foi efetuado um estudo epidemiológico em rebanho de vacas movidas para uma área de transição entre Pantanal baixo e planalto do Estado de Mato Grosso do Sul para determinar a dinâmica de infecção do T. vivax e o risco de surto. Três grupos experimentais foram formados: Grupo 1; composto por vacas parasitologicamente negativas no teste de Woo e no exame sorológico de imunoadsorção enzimática para detecção de anticorpos contra T. vivax (Tv-ELISA-Ab); Grupo 2, vacas negativas parasitológicamente e com reação positiva no Tv-ELISA-Ab; e no Grupo 3, positivas parasitologicamente e no Tv-ELISA-Ab. Durante 24 meses o deslocamento das vacas entre esses grupos experimentais foi determinado pelo monitoramento mensal realizado pelo teste de Woo e Tv-ELISA-Ab. Durante esse período a população de tabanídeos na área experimental foi determinada e as maiores populações ocorreram no período das chuvas. Parasitemias de T. vivax foram detectadas apenas nas quatro primeiras amostragens do período experimental, apesar da elevação de incidência determinada sorológicamente tenha ocorrido no período seco do ano. Portanto, T. vivax foi endêmico no rebanho e a ausência de manifestação clínica sugere que os bovinos sejam tripanotolerantes e o risco de surto seja nulo nas condições em que o experimento foi executado, pois a manifestação clínica da doença esta associada à presença de parasitemia.