Simulium (Hearlea) Vargas, Martinez Palacios, & Diaz Najera 1957

Simulium (Hearlea) Vargas, Martínez Palacios & Díaz Nájera

(Hearlea) Vargas, Martínez Palacios & Díaz Nájera, 1946. Type species: Simulium canadense Hearle.

Female: Wing length, 2.5–5.0 mm. General coloration blackish brown; scutum blackish with 1+1 silvery vittae joining (Figs. 1F, G) or not (Figs. 1H, I) to 1+1 anterior submedian, subtriangular or subquadrate spots, and bordered laterally and posteriorly by silver pruinose areas. Legs yellowish to grayish brown, with apices dark brown­black. Frons convergent below (Fig. 1A), fronto­ocular triangle deep, about as long as wide (Fig. 1B); maxillary palpus with sensory vesicle elongate, nearly 1/2 length of basal article (Fig. 2B). Cibarium broadly U­shaped, with basal portion often thickened, medially cleft, and without strong teeth, although often with wrinkles or small serrations situated upon pair of sublateral, subovoidal prominences (Figs. 2A, F, G). Basal sector of R bare. Sc with 6–18 setae ventrally. Hind basitarsus 5.7–6.0 times longer than broad (Fig. 1C); claw with small, subbasal tooth (Figs. 1D, E). Gonapophysis subtriangular, with blunt apex, gradually concave internal margins, surpassing posterior margin of sternite VIII (Fig. 2C). Anal lobe subquadrate to subrectagular, sparsely haired, except for truncate distal margin (Fig. 2D). Genital fork with stout, capitate rod and apically expanded tines bearing strong anteriorly directed apodemes (Figs. 5E, H). Spermatheca ovoid, with internal spicules (Fig. 2I).

Male: Wing length, 2.6–5.0 mm. General coloration similar to female, differing as follows: Scutum generally velvety black with anterior 1/3 having whitish pruinosity (Fig. 3A). Sc typically bare. Hind basitarsus (Fig. 3B) 2.7–3.6 times longer than broad. Basistylus subquadrate, with small protuberance on external margin. Dististylus thin, elongate, 1/ 3 longer than basistylus, with small haired subbasal carina posteriorly, and one subapical spine (Figs. 3C, F). Ventral plate subquadrate, with narrow median carina (Figs. 3D, G). Endoparameres with broad base and numerous strong hooks (Fig. 3E). Median sclerite subrectangular.

Pupa: Cocoon slipper or shoe shaped, typically neatly and coarsely woven and with or without reinforced anterior margin; length at base ca. 3.5–4.5 mm (range = 2.4–7.0 mm) (Figs. 4–5). Gill inflated, gradually flattened, pseudosegmented (annulated), and lacking secondary branches (Figs. 4–5) to cylindrical, smooth, with having secondary branches (Fig. 6). Frontoclypeus gradually swollen basally (Figs. 3H, I). Frontoclypeus and anterodorsum of thorax smooth or covered with abundant impressed (concave) platelets or rounded or pointed (elevated) granules. Frontoclypeus with 2+2 frontal and 1+1 facial setae. Thorax with 3(4)+3(4) dorsocentral and 2+2 dorsolateral stout trichomes. Abdominal chaetotaxy as in Figure 7. Setae of abdominal tergite I relatively short, hairlike, with small platelets along anterior margin; setae of abdominal tergites II–VI short, slender. Tergites II–IV with 4+4 retrorse hooks, those of tergite II smaller; tergites V–VIII with minute spine combs. Tergite X with or without pair of terminal spines. Sternites IV–VII with small, wrinkled areas.

Larva: Body length, 6.5–12.0 mm. Posterior portion of body typically dorsally flattened and gradually distended ventrally (Fig. 9G); body without evident setae. Cervical sclerites free or adjoining posterior margin of postgena (Fig. 8D). Antenna longer than labral fan stalk, with proximal article elongate and deeply incised, creating segmented appearance; medial article longer than basal and distal (Figs. 8E, K). Cephalic apotome faintly darkened basally, typically lacking discernible headspots (Fig. 9D). Labral fan with 39–54 primary rays. Mandible with strong lateral process, robust intermedial and internal teeth, and two narrow marginal teeth (Figs. 8C–G). Postgenal cleft somewhat blunt to deeply incised apically (Figs. 8A, H, I); hypostomal bridge generally shorter than hypostomal height, ratio of hypostoma:hypostomal bridge = 0.7–1.5:1.0; anterior margin of hypostoma straight or curved (Figs. 8B, J), with median tooth longer than corner teeth. Anal sclerite sometimes encircling posterior circlet. Posterior portion of abdomen often with accessory plates (Figs. 9D, I, J). Rectal papillae of three major lobes, each with 15–78 secondary lobules. Posterior circlet with 102–400 rows of 16–27 hooks.

Bionomics: Immature stages are typically found on stones or vegetation in torrenticolous streams between 10–21°C in temperature at altitudes between 1000–3000m. Feeding habits of females are unknown.

Keys

Female (S. nigricorne and S. temascalense, inseparable from several species) S. chiriquiense unknown.

1 Scutum with silvery submedian vittae joining 1+1 anterior silvery spot (Figs. 1F, G). 2

­ Scutum with silvery submedian vittae not adjoining 1+1 anterior silvery spots (Figs. 1H, I)............................................................................................................................ 7

2 Wing length 2.5–2.7 mm ..................................................................................... estevezi

­ Wing length> 3.0 mm.................................................................................................. 3

3 Cibarium with 1+1 spindle­shaped phalanges in space between arms (Fig. 2G)......... 4

­ Cibarium lacking 1+1 spindle­shaped phalanges in space between arms.......... ayrozai

4 Scutum with anterior submedian 1+1 silvery spots subquadrate (Figs. 1 F, G)............ 5

­ Scutum with anterior submedian 1+1 silvery spots subtriangular (Figs. 1 H, I).......... 6

5 Posterior margin of tergites II–V grayish ....................................................... canadense

­ Posterior margin of tergites II–V not grayish...................................................... juarezi

6 Cibarium with anterior rim thin (Fig. 2F); wing length 3.1 mm.................... delatorrei

­ Cibarium with anterior rim thick (Fig. 2G); wing length 3.4–3.6 mm............................................................................................................ dalmati + ethelae + larvispinosum

7 Cibarium with acute indentation in space between arms (Fig. 2A)............................. 8

­ Cibarium with shallow indentation in space between arms (Fig. 2G)....................... 11

8 Scutum with anterior 1+1 submedian silver spots subtrapezoidal to subquadrate....... 9

­ Scutum with anterior 1+1 submedian silver spots subtriangular......... microbranchium

9 Wing length 2.7–3.1 mm............................................................................................. 10

­ Wing length 3.4 mm...................................................................................... menchacai

10 Wing length 2.7–2.8 mm; scutum with anterior submedian 1+1 silver spots subtrapezoidal................................ ............................................................................. capricorne

­ Wing length 2.9–3.1 mm; scutum with anterior submedian 1+1 silver spots subquadrate ............................................................................................................................... burchi

11 Wing length ca. 5.0 mm............................................................................... contrerense

­ Wing length less than 4.0 mm................................................................................... 12

12 Wing length 3.7–3.9 mm; scutum with anterior submedian silvery spots subtrapezoidal......................................................................................................................... carolinae

­ Wing length <3.2 mm; scutum with anterior submedian silvery spots subtriangular........................................................................................................ gorirossiae + johnsoni

Pupa

1 Gill branches cylindrical, smooth, with 4 or more secondary branches (Fig. 6). Cocoon typically slipper shaped (Figs. 6 A, J)......................................................................... 2

­ Gill branches flattened or subcylindrical, with noticeable wrinkling or annulations and lacking small secondary branches (Figs. 4–5). Cocoon generally shoe shaped (Figs. 4A, J, L; 5A, G)........................................................................................................... 7

2 Secondary (ventral) gill branches smaller than primary anterodorsal branch. Ventral branch with 2 secondary accuminate processes; anterior margin of cocoon neatly woven....................................................................................................................................... 3

­ Secondary gill branches as large as primary anterodorsal branch (Figs. 6J, K). Ventral branch with 6–7 secondary, accuminate processes; anterior margin of cocoon ragged......................................................................................................................... menchacai

3 Gill with primary anterodorsal branch accuminate (Figs. 6F, G).................................. 4

­ Gill with primary anterodorsal branch blunt (Figs. 6 A–E, H, I)................................. 5

4 Frontoclypeus and thorax with sparse granules........................................... gorirossiae

­ Frontoclypeus and thorax lacking granules............................................... temascalense

5 Frontoclypeus and thorax with abundant granules. Cocoon with reinforced anterior margin............................................................................................................. carolinae

­ Frontoclypeus and thorax with, at most, sparse granules. Cocoon without or with only slightly reinforced anterior margin............................................................................... 6

6 Secondary gill branches strongly spinulate (Figs. 6H, I). Frontoclypeus lacking granules ........................................................................................................................... johnsoni

­ Secondary gill branches blunt or weakly spinulate (Figs. 6 A–D). Frontoclypeus and thorax with minute nonelevated to indented granules, particularly at intersection of these structures........................................................................................ larvispinosum

7 Gill with 2 main branches: dorsal and ventral.............................................................. 8

­ Gill with 3 main branches: dorsal, medial, and ventral............................................... 12

8 Cocoon shoe shaped (Figs. 4A, J, L)............................................................................ 9

­ Cocoon slipper shaped (Figs. 4D, F).......................................................................... 11

9 Dorsal gill branch 1.8 times longer than ventral branch and strongly curved (Figs. 4J, K).............................................................................................................. microbranchium

­ Dorsal gill branch 0.6–1.0 times as long as ventral branch and weakly curved (Figs. 4 B, L–N)..................................................................................................................... 10

10 Gill protruding well beyond anterior margin of cocoon (Figs. 4 L–N). Apex of gill branches blunt............................................................................................... nigricorne

­ Gill largely concealed by cocoon (Figs. 4 A–B). Apex of gill branches accuminate.... ............................................................................................................................. ayrozai

11 Dorsal gill branch accuminate, subequal in thickness to ventral branch, and only slightly curved apically (Figs. 4F–I)........................................... ethelae + chiriquiense

­ Dorsal gill branch blunt, twice as thick as ventral branch, and strongly curved apically (Figs. 4D, E).................................................................................................. capricorne

12 Medial gill branch subglobose, inflated, tuberculated, not annulated, except basally (Figs. 5N, O).............................................................................................................. 13

­ Medial gill branch subcylindrical, scarcely or not tuberculated or annulated…............... 14

13 Dorsal and medial gill branches inflated, medial branch membranous ventrally; ventral branch small and subannulated.................................................................... contrerense

­ Medial gill branch inflated, dorsal and ventral branches thin, subannulated (Figs 5N, O).................. ....................................................................................................... juarezi

14 Medial gill branch rounded or weakly to strongly accuminate distally (Figs. 4C, 5C–F, G–I)............................................................................................................................ 15

­ Medial gill branch thickened and capitate distally (Figs. 5A, B, J–M)...................... 17

15 Dorsal gill branch with small ventral protuberance near midlength (Figs. 5C, G).... 16

­ Dorsal branch lacking ventral protuberance (Fig. 4C) ................................... canadense

16 Dorsal gill branch with apex blunt (Figs. 5C–F). Frontoclypeus with platelets laterally, medially with only puntuation (Fig. 3I) .......................................................... delatorrei

­ Dorsal gill branch with apex accuminate (Figs. 5G–I). Frontoclypeus with platelets on entire surface ....................................................................................................... estevezi

17 Dorsal gill branch globose apically, with well developed tubercles. Cocoon shoeshaped (Figs. 5A, B) ............................................................................................. burchi

– Dorsal gill branch with 3 apical prominences, lacking tubercles. Cocoon slipper– shaped (Figs. 5J–M)........................................................................................... dalmati

Larva (mature). (S. nigricorne unknown)

1 Hypostoma with anterior margin convex and with intermedian teeth above level of corner teeth (Fig. 8J). Posterior portion of abdomen with accessory plates (Figs. 9B–E)....................................................................................................................................... 2

­ Hypostoma with anterior margin straight, intermedial teeth shorter than corner teeth (Fig. 8B). Posterior portion of abdomen without accessory plates (Figs. 9A).............. 8

2 Posterior portion of abdomen with only 1+1 accessory dorsolateral plates; ventral strut short, not encircling base of posterior circlet (Figs. 6B, C). Posterior circlet with about 400 rows of hooklets................................................................... S. paracarolinae n. sp

­ Posterior portion of abdomen with 2+2 accessory dorsolateral plates (Figs. 6D, E); ventral strut of anal sclerite encircling base of posterior circlet (Figs. 9D–I). Posterior circlet with <300 rows of hooks................................................................................. 3

3 Posterior portion of abdomen without ventrolateral accessory plates............. carolinae

­ Posterior portion of abdomen with stout ventrolateral accesory plates (Figs. 9D, H–J)........................................................................................................................................ 4

4 Lobes of accessory ventrolateral plate shallowly incised (Figs. 9H, I [vl]). Segment VIII without ventrolateral papillae............................................................................... 5

­ Lobes of accessory ventrolateral plate deeply incised (Fig. 9D [vl]). Segment VIII with well defined, sclerotized ventrolateral papillae (Figs. 9 D–F [vp])..................... 6

5 Labral fan with 43–48 primary rays; anal sclerite with 1+1 dorsal subrectangular flattened accessory plates (Figs. 9 H, I [df]) .................................................. larvispinosum

­ Labral fan with 56 primary rays; anal sclerite without dorsal accessory plates johnsoni

6 Accessory ventrolateral plates of posterior portion of abdomen with anteriorly directed accuminate processes. Posterior circlet with 310 rows of hooks.................. menchacai

­ Accessory ventrolateral plates of posterior portion of abdomen with anterolaterally directed accuminate processes. Posterior circlet with 242–282 rows of hooks............ 7

7 Accessory ventrolateral plates of posterior portion of abdomen strongly toothed (Fig. 9 D [vl]).Ventrolateral papillae of sternite VIII with accuminate tubercles(Figs.9D–F [vp])...................................................................................................................... gorirossiae

­ Accessory ventrolateral plates of posterior portion of abdomen with serrated margin (Fig. 9 J [vl]). Ventrolateral papillae of sternite VIII smooth .................... temascalense

8 Rectal papillae with 60–78 lobules............................................................................... 9

­ Rectal papillae with 45 or fewer lobules.................................................................... 12

9 Rectal papillae with 72–78 lobules. Length of mature larva <7.0– 7.7 mm............... 10

­ Rectal papillae with 60–66 lobules. Length of mature larva> 12 mm ......... contrerense

10 Posterior circlet with about 114 rows of hooks. Labral fan with 39–40 primary rays ......................................................................................................................... delatorrei

­ Posterior circlet with about 172–204 rows of hooks. Labral fan with 46–57 primary rays..................................................................................................................................... 11

11 Posterior circlet with 172–178 rows of hooks. Labral fan with 46–54 primary rays.................................................................................................................................... burchi

­ Posterior circlet with 194–206 rows of hooks. Labral fan with 56–57 primary rays.................................................................................................................... microbranchium

12 Body length 8–10 mm. Hypostoma with 11–17 lateral setae...................................... 13

­ Body length 7–8 mm. Hypostoma with 10 or fewer lateral setae............................... 15

13 Labral fan 42–44 primary rays. Ratio length of hypostoma/length of hypostomal bridge = 0.8....................................................................................................... dalmati

­ Labral fan 48–56 primary rays. Ratio length of hypostoma/length of hypostomal bridge = 1.0............................................................................................................... 14

14 Posterior circlet with 18–20 hooklets per row. Rectal papillae with 15–24 lobules....................................................................................................................... canadense

­ Posterior circlet with 24–27 hooklets per row. Rectal papillae with 36–45 lobules.................................................................................................................................... ayrozai

15 Body length 7 mm. Labral fan with 36–40 primary rays ..................................... ethelae

­ Body length 7.3–8.0 mm. Labral fan with 42–50 primary rays................................. 16

16 Body length 8 mm. Posterior circlet with 98–104 rows of 24–30 hooks ............ estevezi

­ Body length 7.5–7.7 mm. Posterior circlet with 115–145 rows of 15–24 hooks....... 17

17 Posterior circlet with 145 rows of ca. 17 hooks................................................. juarezi

­ Posterior circlet with 115–135 rows of 20–24 hooks.................................... capricorne