Contaminación del agua y distribución de la mosca negra (Diptera: Simuliidae) en el bosque Atlántico, Brasil

Abstract

Black flies have medical importance because some species are vectors of the Onchocerciasis and Mansonelosis, nevertheless, their ecology and potential use as bioindicators is still poorly studied in the Neotropical Region. In Brazil, bioindicators use is strongly focused in a multimetrical ecological index approach; this way, we investigated the black fly spatial distribution, in relation to abiotic factors correlated to water quality, to provide baseline information for their utilization as standalone indicators of lotic systems integrity. We have tested the hypothesis that environmental changes related to urbanization, lead to decreased abundance and loss in the number of species of the black fly fauna. The sampling was conducted in 10 urban and 10 preserved streams during the dry season (August-September) of 2012, in the mountainous region of Teresópolis, State of Rio de Janeiro, Brazil. The streams were characterized for their environmental integrity conditions and physico-chemical properties of water. In each stream, five different rapid points were sampled in a section of 50 meters, 10 meters apart from each other. The black flies were sampled with a kick-net sampler on rocky substrates. The material was separated and the larvae were sorted in morphotypes, and later, the final instar specimens were dissected and identified with the help of taxonomical literature at species level. A total abundance of 488 larvae from nine species were collected, 5 (1.02 %) in extremely impacted streams, 470 (96.31 %) in intermediate streams and 13 (2.66 %) in preserved streams. The visual evaluation (HII) differed in relation to the water physico-chemical evaluation, in which more variation in the characterization of the sampling sites was observed. In Canonical Correspondence Analysis Simulium subpallidum, S. inscrustatum and S. pertinax were significantly associated with intermediate values of most of the variables, and then to intermediate impacted sites. On the other hand, Lutzsimulium hirticosta, S. subnigrum and Simulium sp. A were associated to low values of chemical variables, and then to more preserved sites. Most studies on the bioindicator potential of Simuliidae have suggested an approach to agricultural impacts, while our results, on the other hand, showed that Simuliidae species were present in streams with intermediate urban pollution impacts, but absent in heavily impacted sites. Thus, our data suggested that some species are associated to more pristine breeding sites, such as L. hirticosta and Simulium sp. A, while others may be good bioindicators of moderately impacted streams, such as S. pertinax, S. subnigrum and S. subpallidum. Rev. Biol. Trop. 63 (3): 683-693. Epub 2015 September 01.

Diversity and spatial distribution of black flies (Diptera: Simuliidae) in the Ijuí river drainage basin, Rio Grande do Sul, Brazil

“…Concerning the species S. incrustatum, which was also frequent in the study area, some authors report a preference of the species for aquatic environments of intermediate levels of pollution (Viviani et al 2012;Docile et al 2015). However, Coscarón (1991) indicates that the immature forms are associated to clean waters, as well as smaller water flows.…”

“…As a result, such studies may contribute to identify factors that may modify the local biodiversity, thus providing subsidies for the conservation of environments. Information on the spatial distribution of black flies in flowing water, which represents the main areas where lothic conditions are suitable for the development of immature stages (streams, creeks, or rivers), are essential to distinguish distribution patterns that were caused by anthropic influence from those of natural occurrence (Strieder et al 2002;Strieder 2005;Strieder et al 2006;Docile et al 2015;Buffolo et al 2016).…”

“…Different from other groups of aquatic organisms, morphological and cytotaxonomic approaches of black flies are well developed and advanced (Adler et al 2004). Consequently, these organisms may serve as models for the study of a lotic community structure and may be good bioindicators of moderately impacted streams (Adler & McCreadie 1997;McCreadie & Adler 1998;Docile et al 2015). Although ubiquitous, the ecology of these insects remains poorly understood, particularly in the Neotropical Region (Hamada et al 2002;Campos-de-Oliveira et al 2015).…”

Distribución altitudinal de macroinvertebrados acuáticos y su relación con las variables ambientales en un sistema fluvial amazónico (Perú)

“…El orden Ephemeroptera también fue uno de los más abundantes y con mayor distribución; Camelobaetidius se asoció con velocidades medias y menores altitudes; Baetodes con mayores velocidades y altitudes, al igual que Anacroneuria (Plecoptera), Atopsyche y Smicridea (Trichoptera), que presentan adaptaciones para esos tipos de hábitats (Bispo, et al, 2006;Schmitt, et al, 2016). Entre los Coleoptera están los asociados a corrientes con velocidades medias: Psephenus (Psephenidae) y Heterelmis (Elmidae), aunque este último es característico de ambientes con altas velocidades y elevado contenido de oxígeno (Manzo, 2013;González-Córdoba, et al, 2020), así como larvas de Simulium (Diptera) (Coscarón-Arias, 2009), que pueden sobrevivir en condiciones temporales de anoxia alimentándose de materia orgánica, por lo que están presentes en diferentes ambientes (Docile, et al, 2015), tal como se recoge en el análisis de ACC.…”

Potential phenotypic plasticity within Simulium nigrimanum Macquart, 1838 (Diptera: Simuliidae) larvae

“…Although black flies (Diptera: Simuliidae) are a cosmopolitan insect family with world wide geographic range, their local occurrence is limited by suitable microhabitat characteristics allowing immature filter feeding black fly larvae to breed develop [1]. Black fly populations are regulated by biotic and abiotic factors, the former being competition, predation, and disease [2,3]; and the latter involving to microhabitat features such as substrate and water velocity [4,5,6,7]. Black flies are key organisms in lotic systems, regarded as ecosystem engineers.…”