The Role of Neotropical Blackflies (Diptera: Simuliidae) as Vectors of the Onchocerciasis: A Short Overview of the Ecology Behind the Disease

Abstract

The Blackflies (Diptera: Simuliidae) are a cosmopolitan dipteran family, comprising 2102 described species. Although insects of this family are widely distributed, their immatures are restricted to areas where suitable lotic conditions allow their development. While the Onchocerciasis has been largely studied over the years, it still lacks a more integrated approach with the vector ecology. In this paper, we examine the ecological factors that potentially play a role in the disease dynamics. Our aim is to identify the ecological factors that are potentially important in the vector dynamics and the gaps in the current knowledge of blackfly ecology that could lead to a better understanding of the underlying factors behind the disease dynamics.

Evidence of phenotypic plasticity of larvae of Simulium subpallidum Lutz in different streams from the Brazilian Cerrado

“…Figueiró and Gil-Azevedo (2010) reported the scarcity of studies on microhabitat requirements of Neotropical black flies and the lack of studies relating labral morphology to microhabitat type in the Neotropics. Figueiró et al (2012) recently observed that Simulium subpallidum Lutz, 1909, in the presence of Simulium nigrimanum Macquart, 1838, was restricted to velocities between 0.19 m.s -1 and 0.88 m.s -1 , while the later occupied velocities between 0.99 m.s -1 and 1.32 m.s -1 .…”

Diversity and microdistribution of black fly (Diptera: Simuliidae) assemblages in the tropical savanna streams of the Brazilian cerrado

“…Black fly larvae were sampled from the Tocantins River and three tributaries, located in the Brazilian savanna (state of Tocantins, Brazil) Key words: Neotropical Region -microhabitat associations -diversity -species richness -water current range Hamada et al (2002) pointed out the relative scarcity of ecological studies on the black fly fauna of the Neotropical Region. In addition to this limited number of studies, most of the literature on this subject is restricted to a few geographical areas; in the specific case of Brazil, a large number of biomes lack ecological studies on their black fly fauna (Figueiró & Gil-Azevedo 2010), as most of the studies concentrate on the central Amazon (e.g., Hamada et al 2002), southeastern (e.g., Araújo-Coutinho et al 2004, Figueiró et al 2006, Pepinelli et al 2005) and southern (Strieder 2004, Santos et al 2010 Mata Atlântica biomes. Another issue raised in Hamada et al (2002) is that most of the studies on Neotropical black flies approach the ecology of the individual species population (e.g., Hamada & McCreadie 1999), rather than the whole black fly community.…”

Environment & Health: perspectives and challenges

“…While the notion of the intimate link between environment and infectious diseases has been well established over the years, most of the studies that deal with disease dynamics often approach these systems in a simplistic manner: as three (pathogen, vector, host) or four (when a reservoir is also involved) compartments model (Figueiró & Gil-Azevedo, 2010). This can be an useful approach for short term predictions and interventions, as noted by Ellis & Wilcox (2009), however, this typical epidemiological simplified model which ignores the interactions between the the populations directly involved in a given disease dynamics and the rest of the biological communities they belong to has limited application for longer term predictions.…”