Pre-imaginal black fly assemblages in streams of Eastern Spain: environmental and substrate requirements

Environmental drivers of breeding sites in blackfly species of medical and veterinary importance in eastern Spain

“…This directly targets one of the most challenging questions in biological control regarding whether natural antagonists provide enough limitation of the abundance of a pest due to the effects of competition for a shared resource, in this case substrate availability, or not. Previous studies have suggested no particular substrate preference for the set of species studied here (López-Peña et al, 2020), so competition may occur for any empty space on the riverbed.…”

“…This result is consistent with the pupal habitat analysis of the local abiotic variables. Previous studies have highlighted the role of both meteorological and topographic factors, such as temperature and elevation, in shaping blackfly assemblages (McCreadie & Adler, 2006, 2014Ya'cob et al, 2016;López-Peña et al, 2020), however we did not include elevation in the set of variables used in the CCA as it was included in the dataset of abiotic variables and it showed a high negative correlation with annual average temperature (R 2 > 0.8, P value <0.001). Regarding the other landscape variables, our results suggest that breeding sites of S. (W.) equinum are positively associated with the presence of pig farms within a radius of 35 km around sampling sites, whereas those of S. (S.) reptans were found closer to cattle farms and within shorter distances from them.…”

“…The ecological characterization of blackfly breeding habitats has been intensified in Europe since the 1980s (Hansford & Ladle, 1979;Rivosecchi, 1986;Leclercq, 1987;Ignjatović-Ćupina et al, 2006) and in the north of Africa (Arigue et al, 2016;Belqat et al, 2018), but there is still a paucity of data concerning some European regions, such as the Mediterranean region. This is especially true in Spain, where populations of pest species including Simulium (Boophthora) erythrocephalum (De Geer, 1776), S. (Simulium) ornatum (Meigen, 1818), S. (S.) reptans (Linnaeus, 1758), S. (Wilhelmia) equinum (Linnaeus, 1758), S. (W.) lineatum (Meigen, 1804) and S. (W.) pseudequinum (Séguy, 1921), have recently increased their population sizes and geographical ranges and have thus become an emerging issue of public health and veterinary concern (López-Peña & Jiménez-Peydró, 2017;López-Peña et al, 2020), although the increase in their annoyance to humans may be explained by other factors such as increasing anthropophagic tendencies, changes in species compositions, decreased tolerance by people, increased knowledge resulting in more frequent reporting of the problem, etc.…”

"Health Risks of Simulium (Boophthora) erythrocephalum (De Geer, 1776) in the Valencian Autonomous Region, Eastern Spain"

“…Finally, simuliid species with obligate hematophagy of biomedical and veterinary importance [27] such as S. erythrocephalum are generalist species regarding the type of habitat in which they develop, Therefore, these species are capable of tolerating a wide range of ecological conditions. Under this premise and given the current climate change scenario in which certain authors and institutions predict a decrease in coldwater river habitats and greater environmental variability [28], it would be expected that the resulting conditions would favor the distribution and colonization of S. erythrocephalum to new geographic areas, increasing its harm to the well-being of citizens.…”

“…In this way, the knowledge of the bioecology of the species will play a crucial role when it comes to implementing treatment plans for preimaginal states, minimizing the sizes of their populations and reducing their incidences in public health. In the case of S. erythrocephalum, it is important to know that it is a species whose preimaginal development optimum is 20°C, tolerates values higher than 25°C, shows a narrow range of altitudinal tolerance with its optimum around 75 meters above sea level (masl), so that its distribution in the Valencian Autonomous Region is restricted to elevations between 5 and 240 masl [27]. Likewise, some authors ecologically described this species as preferring lentic and warm waters typical of the middle and lower sections of rivers [30].…”