Simulium (Psilopelmia) machetorum Mantilla, Moncada, Matta & Adler, 2013, new species
Creators: name: Mantilla, Juan S.
name: Moncada, Ligia I.
name: Matta, Nubia E.
name: Adler, Peter H.
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Simuliidae
Simulium
Simulium machetorum

description: Simulium (Psilopelmia) machetorum new species
(Figs. 2, 3 D–F, 4E–H)
FEMALE (dissected from pupa) (Fig. 2 A). General body color dark brownish; all hair dark brownish to brassy, except recumbent hair on scutum golden.
Head— Frons pollinose, longer than greatest width, with dark hairs. Head about 3.8–4.0 times longer than greatest width of frons. Maxillary palp with sensory vesicle about 3/8 length and ½ width of palpomere III; palpomere V about 6 times longer than greatest width. Antenna with 9 flagellomeres; first flagellomere longest, with dark hairs. Lacinia with 17 teeth. Mandible with 30–32 teeth. Cibarium with well-sclerotized cornuae; median region unarmed or with few minute teeth centrally.
Thorax— Length 1.4–1.5 mm (n = 2). Scutum grayish black; lateralmost margins grayish. Scutellum ocher with numerous long black and bronze hairs, depending on angle of lighting. Postnotum grayish black, with golden pruinosity. Wing with stem vein and basicosta bearing dark brownish hairs; subcosta with row of setae ventrally; radius dorsobasally with hair. Legs dark brownish. Claws each with small subbasal tooth.
Abdomen— Tergite VI with central grayish spot; VII entirely grayish. Cercus (Fig. 2 A) subrectangular, about 2 times wider than long. Anal lobe (Fig. 2 A) subtriangular, sclerotized posteriorly, membranous and covered with microtrichia anteriorly, about 3 times as deep as long, projected ventrally as rounded process. Hypogynial valve with inner margin well sclerotized and lacking microtrichia. Genital fork slender; arms nearly of uniform thickness, about same width as stem, expanded distally into small lateral plates. Spermatheca subspherical, with microspines internally and hexagonal network externally; junction with spermathecal duct unpigmented.
MALE (Figs. 2 B–I). All body parts dark brown to blackish; all hair brassy.
Head— Frons and occiput with silvery pruinosity and long hairs. Antenna with scape bearing outer tuft of setae up to 4 times longer than width of scape; pedicel about 1.1 times wider than long; flagellum of 9 flagellomeres, with first longest and widest, about 1.3 times longer than wide, about 2 times longer than 2nd, and 1.7 times longer than pedicel. Maxillary palp with sensory vesicle less than ¼ length of its palpomere; palpomere II, and especially III, with long hairs up to about 2 times longer than palpomere III.
Thorax— Length 1.3–1.5 mm (n = 2). Scutum without markings, with medium-long, posteriorly directed hairs; posterolateral border with long, anteriorly directed hairs; scutellum with lateral tufts of long, anteriorly directed hairs. Postnotum with silvery pruinosity. Katepisternum bare. Wing with subcosta bearing hairs ventrally; radius with hair dorsobasally. Halter with stem grayish, club whitish yellow. Legs dark brownish. Calcipala rounded, 1/3 or less width of apex of its segment; pedisulcus about ½ depth of tarsomere I.
Abdomen— Tergites VI, and slightly V, shiny, with silvery pruinosity. Genitalia: Gonocoxite in ventral view subtrapezoidal, about 1.3–1.5 times wider than long, slightly shorter than gonostylus. Gonostylus in ventral view, as viewed in situ (Fig. 2 C), smoothly curved toward midline, 2.3–2.4 times longer than basal width; in dorsal view (Fig. 2 B) proximal ¾ about 2.6 times wider than distal ¼; in lateral view (Fig. 2 D) smoothly curved, with 1 slender subapical spinule. Ventral plate in ventral view subrectangular, rounded posterolaterally, with body of plate about 1.8 times wider than long in situ (Fig. 2 E), or 1.6 times wider if lip tilted ventrally (Fig. 2 F) so that lip is conspicuous; in lateral view (Fig. 2 G) lip narrowed, projected ventrally from body of plate in smooth curve at 90° or slightly greater angle to arm. Median sclerite (Fig. 2 H) short, abruptly widened in distal half to irregularly rounded, weakly sclerotized area about as wide as long. Paramere (Fig. 2 I) subquadrangular, wrinkled, connected to series of 2–4 stout spines interspersed with numerous smaller spines about ¼ to ½ as long as largest spine. Aedeagal membrane with rows of microsetae.
PUPA (Figs. 2 J, 3D–F, 4H). Total body length (without gill) 3.5-4.2 mm.
Head— Cephalic plate with irregularly and densely distributed, acuminate tubercles; row of 7 or 8 arborescent frontal trichomes with about 14 branches each; 1 arborescent trichome (ca. 10 branches) on each eye sheath posterolateral to antennal sheath.
Thorax— With fine covering of uniformly spaced, fine microgranules, and irregularly distributed acuminate microtubercles (Fig. 3 E, F), less dense and less robust than on cephalic plate, and progressively less dense and smaller posteriorly; row of 5 arborescent trichomes with about 14 branches (Figs. 3 E, F).
Gill (Fig. 4 H) — Length 2.0– 2.9 mm (n = 2); with 6 filaments in 3 pairs arising from short trunk slightly longer than wide; dorsal pair of filaments with petiole about 2 times longer than wide; middle and ventral pairs with petiole about 6–8 times longer than wide; all filaments subequal in width, with furrowed surface.
Abdomen— Tergite I with 1 small seta per side; tergite II with row of 3 or 4 small, short, unbranched, anteriorly directed setae and lateral cluster of 3 slender, unbranched, straight setae per side; tergites III and IV each with 4 anteriorly directed hooks and 1 or 2 small setae per side; tergites V and VI each with several rows of comblike scales; tergite VII with variable number of setae per side and several rows of minute comblike scales; tergite VIII with 9 spines of different sizes per side and several rows of minute comblike scales; terminal spines minute. Sternite III with 1 small seta per side; sternite IV with 1 anteriorly directed hook per side; sternite V with 2 anteriorly directed, bifid or trifid hooks per side; sternite VI with 1 unbranched hook, 1 bifid hook, and 1 small trifid seta per side; sternite VII with 1 anteriorly directed unbranched hook, 1 bifid hook, and several rows of minute, comblike scales per side; sternite VIII with several rows of minute, comblike scales per side. Pleural region on each side with 0–2 small setae per segment.
Cocoon (Fig. 2 J) — Length ventrally 3.5–4.8 mm (mean 4.2 mm, n = 6); slipper shaped, with pair of elongated anterodorsal projections (length 1.8–2.3 mm, mean 2.1 mm, n = 6) sometimes reaching substrate; individual threads distinct; anterior border reinforced with silk.
LARVA (mature) (Figs. 4 E–G). Total length 7.6 mm (n = 1). General body color grayish, with slight greenish cast.
Head— Dark chestnut brown, lightest on anterior of cephalic apotome (Fig. 4 E); head spots faintly negative within darker subtriangular area; cervical sclerites dark brown, minute, ovoid, free of postocciput; line over eye yellowish brown. Antenna brownish, subequal in length to stem of labral fan; ratio of articles proximal to distal including apical cone sensillum: 1.0: 1.7: 1.4; proximal article unpigmented ventrobasally, medial article with minute translucent spot proximally and distally. Labral fan with 49 primary rays. Mandible with largest tooth slightly serrated along inner margin; sensillum bifid. Maxillary palp with darkly pigmented area about 1.7 times as long as its basal width and extended to about 82% of palp length. Hypostoma (Fig. 4 F) with anterior margin concave, middle and lateral teeth subequal in prominence; 7–11 lateral serrations per side; 5–8 tufted sublateral setae per side, plus 2 or 3 additional, smaller, unbranched or bifid setae per side and about 8 small, unbranched setae scattered on central disc. Postgenal cleft (Fig. 4 G) subtriangular, extended about 60% of distance from posterior tentorial pits to hypostomal groove.
Thorax— Lateral plate of prothoracic proleg subtriangular, well sclerotized, light brownish. Gill histoblast with 6 filaments in 3 pairs.
Abdomen— Rather abruptly expanded at segment V; ventral tubercles absent. Abdominal cuticle without conspicuous setae. Rectal papillae of 3 lobes with 18–20 lobules each. Anal sclerite with anterior arms broad; posterior arms slender, darker, and slightly longer than anterior arms. Posterior circlet with 88 rows of 10–15 hooklets each.
HOLOTYPE. Male (dissected from pupa) pinned with pupal exuviae and cocoon in glycerin microvial below. COLOMBIA, Department of Risaralda, W side of Cordillera Central Andes, Nevado de Santa Isabel, Lake Otún (4°47'41.9”N 75º24'29.1”W), 3950 masl, 11 January 2012, collectors L. Madroñero, E. Ruiz, S. Mantilla (deposited in Instituto de Ciencias Naturales (ICN), Bogotá, Colombia, accession number ICN-086082). PARATYPES. Same locality and collectors as for holotype, 27 June 2010 (1 pupa with pharate female on slide, 1 pupa with pharate female in 80% ethanol and terminalia in glycerin, 3 pupae on slides, 2 pupae in 80% ethanol, 1 larva in 80% ethanol, 1 larva on slide); 29 December 2010 (3 pharate males in glycerin vials on pins, 1 larva in glycerin vial on pin). Accession numbers ICN-086086, ICN-086093, ICN-086094, and ICN-086095.
Etymology. This species is named in recognition of the Machete family, who farms the area near the type locality and provided field assistance. The species name also represents a typical working tool of Colombian farmers, the machete, and therefore, also honors all Colombian people working in the countryside.
Habitat. Larvae and pupae were found in flows less than 2 m wide, with water temperature of 3.3–6.5 °C (mean 4.8 °C), pH 7.8–8.1 (mean 7.9), dissolved oxygen 7.2–7.8 mg /l (mean 7.6 mg /l), and 0–50% coverage by riparian vegetation. Pupae were found only on trailing vegetation. Larvae and pupae were found in low numbers, compared with populations of other species in the habitat (G. arrarteorum, G. basinflatus, G. misitu, and S. quimbayium n. sp.) Pupae were found in the middle and end of the year.
Remarks. We place this species in the subgenus Psilopelmia (sensu Shelley et al. 2010), based on the morphology of the female and male genitalia. It is, however, an unusual member of the subgenus, particularly in having expansive anterodorsal projections on the cocoon and uniformly dark adults, the latter feature perhaps related to the high-altitude environment. The configuration of the gill is similar to that of S. gabaldoni Ramírez- Pérez and Simulium arcabucense Coscarón, especially the latter in the branching pattern. Simulium machetorum n. sp., however, is distinguished from both species by having cephalic and thoracic microtubercles longer than wide (Figs. 3 E, F) and a pair of long anterodorsal projections on the cocoon (Fig. 2 J). The female of Simulium arcabucense has a similarly shaped anal lobe (as do other species, such as S. pifanoi Ramírez-Pérez), but the scutum is patterned with yellow and brown and the sclerotization pattern of the anal lobe is more extensive. The male genitalia are similar to those of the Simulium romanai Wygodzinsky complex, but differ by the presence of 2– 4 long, stout parameral spines (in addition to numerous smaller spines) (Fig. 2 I), and a more distally broadened median sclerite (Fig. 2 H).
description: Published as part of Mantilla, Juan S., Moncada, Ligia I., Matta, Nubia E. & Adler, Peter H., 2013, Two New Species of Black Flies (Diptera: Simuliidae) from the High Andes of Colombia, pp. 423-434 in Zootaxa 3700 (3) on pages 428-432, DOI: 10.11646/zootaxa.3700.3.6, http://zenodo.org/record/217433