Simulium (Hearlea)
Creators: name: Molina, Óscar S.
name: Gil-Azevedo, Leonardo H.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Simuliidae
Simulium

description: Simulium (Hearlea) Vargas, Martínez Palacios & Díaz Nájera, 1946
Figs 6, 25, 39–40, 57–59, 78–79, 98, 110, 121, 136–139
Hearlea Rubtsov, 1940: 154 (unav., nom. nud.).
Hearlea Vargas, Martínez Palacios & Díaz Nájera, 1946: 106, figs 19–34 (as subgenus of Simulium). Type species: Simulium canadense Hearle, 1932.
Diagnosis
Female
Scutum blackish to dark brown; scutal pattern present (Fig. 6). Cibarium unpigmented anteromedially and unarmed. Tarsal claws with subbasal tooth. Hypoginial valves subtriangular, shorter than sternite VIII width and forwardly directed. Anal lobe subrectangular with ventral extension shorter than cercus base width (Fig. 25).
Male
Ventral plate with sub-equal width and length, with or without anterior notch; lateral shoulders projected or not; posteromedial process present or absent. Gonocoxite wider than long, with base double in width than gonostylus width at their point of intersection (Figs 57–59). Gonostylus cylindrical, distinctly longer than gonocoxite, with blunt apex and apical spinule (Figs 57–59). Parameres with both distinctly large and small accessory spines.
Pupa
Cocoon aperture upward directed or not, not corbicular. Gills shorter than pupa body, with trunk developed, and free or with the base enclosed by the cocoon anterior margin; with 2–12 filaments arranged in the same or in different planes (tridimensional); filaments stiff, swollen, with blunt or acute apices concolorous with rest of gill; inferior branch not multibranched. Thoracic trichomes simples.
Larva (last instar)
Cephalic apotome spots insertion area not pigmented (Fig. 121). Postocciput not extended over the cervical sclerites (Fig. 121). Antenna with ½ of distal antennomere surpassing the labral fan stalk, without secondary annulations. Mandibles with preapical teeth as long as or longer than apical tooth; two mandibular serrations of same sizes. Postgenal cleft triangular; postgenal bridge length equal or less than hypostomal length. Hypostomal anterior margin convex or straight; hypostomal teeth extended beyond anterior margin of ventral wall of hypostoma; medial tooth as prominent as lateral ones or longer; lateral serrations well-developed, sharp; hypostomal paralateral teeth present or absent. Body surface glabrous. Abdomen gradually expanding posteroventrally to last segments, then abruptly contracting to posterior proleg (Fig. 110). Anal sclerite encircling posterior posterior proleg or not. Posterior portion of abdomen with or without sclerotized accessory plates. Without 1+1 ventral tubercles. Rectal papillae with three multi-branched lobes.
Remarks
Simulium (Hearlea) was recovered based on three synapomorphies (Fig. 1, Table 2, node 3), so we propose its revalidation. Coscarón et al. (2004) divided S. (Hearlea) into the species-groups Carolinae and Juarezi. We included two species of Carolinae and three of Juarezi in our analysis and, despite the low number of representatives, both groups were recovered, each defined by three synapomorphies and highly supported (Fig. 1, Table 2, nodes 4, 5).
Based to our results, we maintain S. (Hearlea), which comprises 19 species and is divided into the species-groups Carolinae (Fig. 1, node 4) (seven species) and Juarezi (Fig. 1, node 5) (12 species), as defined by Coscarón et al. (2004). Both species-groups can be differentiated by: male ventral plate; pupal gills and cocoon morphology; larval hypostoma, abdominal posterior sclerotized accessory plates, and anal sclerite.
Carolinae species-group
Species
Simulium carolinae De León, 1945
S. gorirossiae Vargas & Díaz Nájera, 1957
S. johnsoni Vargas & Díaz Nájera, 1957
S. larvispinosum De León, 1948
S. menchacai Vargas & Díaz Nájera, 1957
S. paracarolinae Coscarón, 2004
S. temascalense Díaz Nájera & Vulcano, 1962
Diagnosis
Male
Ventral plate not notched; lateral shoulders not projected; posteromedial process absent (Fig. 40).
Pupa
Cocoon aperture next to the substratum; with 2–12 gill filaments, stiff, swollen, of same thickness, with accessory small branches, and oriented in different planes (tridimensional).
Larva (last instar) Hypostomal anterior margin convex; hypostomal medial tooth distinctly longer than lateral ones. Abdomen with posterior sclerotized accessory plates. Anal sclerite totally encircling base of posterior proleg (e.g., S. carolinae, S. gorirossiae, S. johnsoni, S. larvispinosum, S. menchacai, S. temascalense) or almost (e.g., S. paracarolinae).
Distribution
The group is found exclusively in central and southern Mexico and Guatemala (Adler 2020).
Juarezi species-group
Species
Simulium ayrozai Vargas, 1945
S. burchi Dalmat, 1951
S. canadense Hearle, 1932
S. capricorne De León, 1945
S. contrerense Díaz Nájera & Vulcano, 1962
S. dalmati Vargas & Díaz Nájera, 1948
S. delatorrei Dalmat, 1950
S. estevezi Vargas, 1945
S. ethelae Dalmat, 1950
S. juarezi Vargas & Díaz Nájera, 1957
S. microbranchium Dalmat, 1949
S. nigricorne Dalmat, 1950
Diagnosis
Male
Ventral plate shallowly notched; lateral shoulders projected; posteromedial process present (Fig. 39).
Pupa
Cocoon aperture upward-directed (Figs 78–79); with 2–3 gill filaments, stiff, swollen, of different thickness and length, without accessory small branches, and oriented in the same plane (Fig. 98).
Larva (last instar)
Hypostomal anterior margin straight; hypostomal medial tooth at same level as lateral ones. Abdomen without posterior sclerotized accessory plates. Anal sclerite not encircling base of posterior proleg.
Distribution
Most members of this group occur in central and southern Mexico and Guatemala; S. canadense occurs in Canada and the USA and S. ethelae occurs in Costa Rica and Panama (Adler 2020).
description: Published as part of Molina, Óscar S. & Gil-Azevedo, Leonardo H., 2021, Simulium (Trichodagmia) (Diptera, Simuliidae) phylogeny revisited: the Neotropical and Afrotropical connection, pp. 80-119 in European Journal of Taxonomy 773 on pages 93-97, DOI: 10.5852/ejt.2021.773.1517, http://zenodo.org/record/5542069