A New Anthropophilic Species of Simulium (Trichodagmia) (Diptera: Simuliidae) From Amazonia: Morphology, Chromosomes, and DNA Sequences

Abstract

The black fly Simulium (Trichodagmia) hirtipupa Lutz (Diptera: Simuliidae) is widely distributed in southern Brazil, with one report from Amapá state in the northern region of Brazilian Amazonia. Morphological comparison of northern and southern populations revealed differences in all life stages, corroborated by chromosomal and molecular analyses, and indicated that the population previously identified as S. hirtipupa from Amapá state represents an undescribed species. This new species is described based on all life stages above the egg, and its chromosomal and molecular divergence from S. hirtipupa is highlighted. Simulium criniferum n. sp. can be diagnosed by the deeply concave male ventral plate with a prominent median projection bearing a ventral keel; female anal lobe in lateral view with a broadly rounded, distal membranous area about as long as wide; pupa with a boot-shaped cocoon bearing a minutely bubbled surface, cephalic plate and thorax with abundant hair-like tubercles, and gill of 12 translucent filaments with darkly sclerotized, acuminate tips; and larva with the body cuticle bearing spiniform setae, abdomen truncated posteriorly, and gill histoblast in situ with the filament tips directed ventrally. Chromosomally, the new species has five unique fixed inversions and uniquely shares three additional fixed inversions with its nearest relative, S. hirtipupa. Partial COI sequences indicate a genetic distance of ~9% between the new species and S. hirtipupa. Females of the new species are anthropophilic.

Phylogeography and population diversity of Simulium hirtipupa Lutz (Diptera: Simuliidae) based on mitochondrial COI sequences

“…For instance, a chromosome analysis of populations from the states of Bahia and Goiás showed that they differed from each other in one fixed inversion in three chromosomes, therefore indicating that S . hirtipupa , is a complex with at least two cytoforms [ 26 ].…”

“…Simulium hirtipupa Lutz, 1910 is restricted to Brazil where it is present in four of the five major geographic regions, it is not present in the North region [ 25 , 26 ]. Recently a new species previously identified as a northern population within this nominal species was described as Simulium criniferum [ 26 ].…”

“…Simulium hirtipupa Lutz, 1910 is restricted to Brazil where it is present in four of the five major geographic regions, it is not present in the North region [ 25 , 26 ]. Recently a new species previously identified as a northern population within this nominal species was described as Simulium criniferum [ 26 ]. It occurs in the Brazilian biomes of Caatinga, Cerrado, and the Atlantic Forest, which correspond to the occurrence area of Seasonally Dry Tropical Forests (SDTFs), one of the most endangered ecosystems due to heavy deforestation [ 27 ].…”

“…criniferum is the closest relative to S . hirtipupa and the females of the former are anthropophilic [ 26 ]. These results suggest that the genetic patterns of S .…”

Molecular circumscription of the blackfly Simulium oyapockense from South America

“…Simuliidae has medical and veterinary importance because most species have females with hematophagous habits. This family is known for harbouring many cryptic species that are normally discovered by analysis of polytene chromosomes (e.g., Adler et al, 2010;Nascimento et al, 2018;Post et al, 2007) and by molecular analysis (e.g., Hamada et al, 2010;Nascimento et al, 2020Nascimento et al, , 2021. Distinguishing these species in epidemiological studies and vector-control programmes is important because different species in a complex may exhibit differences in biology, ecology, vector competence, and response to control measures.…”