Oecetis constricta, Blahnik, Roger J. & Holzenthal, Ralph W., 2014

Blahnik, Roger J. & Holzenthal, Ralph W., 2014, Review and redescription of species in the Oecetis avara group, with the description of 15 new species (Trichoptera, Leptoceridae), ZooKeys 376, pp. 1-83 : 24-27

Oecetis constricta sp. n. Figs 7, 56, Map 4

Diagnosis.

This species resembles Oecetis mexicana sp. n. and Oecetis campana sp. n., in its small size, yellow coloration, prominent and distinctly rounded forewing spots, and in the obtuse angle formed between the ventral and dorsal lobes of the inferior appendage. The character most useful in diagnosing this species is the distinctive constricted, or “pinched” apex of the phallobase, as viewed caudally (Figs 7 C–D). It should be noted, however, that in some exceptional specimens assigned to Oecetis mexicana from Panama the apex of the phallobase was rather narrowly U-shaped (Fig. 19C). It appears that the pinched apex of the phallobase in Oecetis constricta is formed, in part, by the asymmetrical phallic sclerite forming a part of the marginal wall of the phallobase, and thus the sclerite is not as projecting as it is in Oecetis mexicana . An additional population from Costa Rica (assigned to Oecetis constricta and listed below under additional material examined) seems to be somewhat intermediate in characters between Oecetis mexicana and Oecetis constricta ; it lacks the distinctive pinched apex of Oecetis constricta , but agrees in other details. It was not included in the paratype material due to its aberrant characters. The COI barcode of a specimen from this series was similar to other specimens of Oecetis constricta ; however, no barcode sequences have yet been obtained for Oecetis mexicana . It is possible that there is some hybridization or introgression occurring between the 2 species and it is also possible that the specimens mentioned may have been misassigned (see remarks section following species description). In general, the 2 species seem to be distinct and their distributions overlap significantly. In a large enough series, it can be noted that Oecetis constricta is slightly darker in color than either Oecetis mexicana or Oecetis campana . Setae on the costal margin of the forewing are slightly longer than in Oecetis mexicana and shorter than in Oecetis campana . Other differences from Oecetis mexicana include its slightly smaller size and a tendency for the phallobase to be more angularly bent ventrally. The ventral lobe of the inferior appendage is always clearly obtusely angled in relation to the dorsal lobe. An additional difference between Oecetis constricta and the other 2 species is that the mesal margins of the inferior appendages, in ventral view, tend to be less angularly diverging (compare Fig. 7F to Figs 6E and 18F).

Adult.

Forewing length: male (6.6-7.8 mm), female (5.5-6.5 mm). Color yellowish with slight brownish cast, slightly darker than Oecetis mexicana sp. n. Antennae pale yellow with indistinct, narrow annulations at intersection of antennomeres. Forewing spots distinct and large; spots at base of discal and thyridial cells largest, spots at base of other major wing forks nearly as large; veins of forewing chord widely and usually nearly evenly spaced, with crossveins nearly perpendicular, or s and r-m veins slightly closer; chord with small spots at juncture of major veins, those at opposite ends of chord larger; apical spots, at apices of major veins prominent, pigmentation extending onto the membrane. Setae on veins in apical part of forewing, semi-prostrate, laterally splayed, and diverging. Fringe of setae along costal margin of forewing moderately dense, elongate, nearly erect.

Male genitalia.

Segment IX very short, with elongate setae along posterolateral margin. Tergum X with narrow, deflexed mesal lobe, apex of lobe lobulate or slightly tapered apically, with small sensilla; lobe continuous basoventrally with short, paired lateral membranous projections. Preanal appendage moderately elongate, length about 3 times maximum width, simple in structure, apical setae elongate. Inferior appendage with prominent rounded dorsal lobe and angularly projecting ventral lobe; ventral lobe moderately projecting, forming distinctly obtuse angle with dorsal lobe, posterior margin of ventral lobe, as viewed ventrally (Fig. 7F), gradually curved outward, not strongly bent at base; basomesal projection weakly developed, scarcely or not protruding, with short, stiff setae; dorsal lobe with stout, mesally-curved setae on dorsal margin and stout, ventrally-curved setae on mesal surface. Phallobase short and tubular, ventral apex distinctly, rather angularly down curved; ventral apex, as viewed caudally, distinctively “pinched” and narrowed, apex U-shaped (Fig. 7C). Phallotremal sclerite prominent, basally forming short tubular collar, ventral margin projecting, apex acute; asymmetrical lateral sclerite present, but may not be evident because it forms lateral wall of “pinched” apex.

Holotype.

Male (pinned), COSTA RICA: San José: Res. Biol. Carara, Río Carara in Carara, 9°46.680'N, 84°31.860'W, el 200 m, 14.iii.1991, Holzenthal, Muñoz, Huisman (UMSP) (UMSP000207959).

Paratypes.

MEXICO: Chiapas: Puente Arroyo Viejo, Rt 200, km 141, 9.vi.1967, Flint & Ortiz, 1 male, 2 females (pinned) (NMNH); Veracruz: Almilmga, nr. El Palmar, Río Tonto, 1.iv.1963, F. Pacheco, 10 males, 4 females (alcohol) (NMNH); GUATEMALA: Río Matapa, 10 km SE Esquintla, el 275 m, 5-6.iii.1970, E.J. Fee, 1 male (alcohol) (NMNH); Suchetepequez: Puente Ixtacapa, 18-19.vi.1966, Flint & Ortiz, 1 male, 3 females (pinned) (NMNH); HONDURAS: El Zamorano, 28-29.i.1966, G.F. Freytag, 1 male, 3 females (alcohol) (NMNH); NICARAGUA: Puente Quinama, E Villa Somoza, 29.vii.1967, O.S. Flint, Jr., 1 male, 1 female (pinned) (NMNH); COSTA RICA: Pedregoso, 21.ii.--, D.L. Rounds, 1 male (pinned) (NMNH); Las Canas, 13.vii.1965, P.J. Spangler, 1 male (alcohol) (NMNH); Guanacaste: P. N. (Parque Nacional) Guanacaste, Maritza, Río Tempisquito, 10°57.480'N, 85°29.820'W, el 550 m, 19-20.vii.1987, Holzenthal, Morse, Clausen, 1 male (pinned) (UMSP); El Hacha, Quebrada Pedregal, 10°58.980'N, 85°32.340'W, el 300 m, 27.vii.1987, Holzenthal, Morse, Clausen, 1 male (pinned) (UMSP); Río Tizate, 7.2 km NE Canas Dulces, 10°46.380'N, 85°26.940'W, el 275 m, 28.vi.1986, Holzenthal, Heyn, Armitage, 1 male (pinned), 2 males, 1 female (alcohol) (UMSP); Heredia: La Selva Field Station nr. Puerto Viejo, 21-28.iii.1988, W. E. Steiner, J. M. Hill, J. M Swearingen & J. M. Mitchell, 1 male, 4 females (pinned) (NMNH); Est. Biol. La Selva, Río Puerto Viejo, 10°26.400'N, 84°0.720'W, 30 m, 10-11.ii.1986, Holzenthal, 1 male (alcohol) (UMSP); Limón: Río Uatsi, ca. 8 km (air) W Bribri, 9°37.200'N, 82°54.000'W, el 60 m, 25.iii.1987, Holzenthal, Hamilton, Heyn, 1 male (pinned) (UMSP); Puntarenas: Res. Biol. Carara, Río Carara, 4.3 km (rd) E Costanera Sur, 9°48.600'N, 84°34.320'W, el 20 m, 12.iii.1991, Holzenthal, Muñoz, Huisman, 6 males, 7 females (pinned), 3 males, 14 females (alcohol) (UMSP); Res. Biol. Carara, Quebrada Bonita, 9°46.500'N, 84°36.300'W, el 35 m, 11.iii.1991, Holzenthal, Muñoz, Huisman, 11 males, 2 females (pinned) (UMSP); same location, 18-20.v.1990, Holzenthal & Blahnik, 7 males, 7 females (pinned), 2 males, 3 females (alcohol) (UMSP); Quebrada Pita, ca. 3 km (air) W Golfito, 8°38.520'N, 83°11.580'W, el 15 m, 15.ii.1986, Holzenthal, Morse, Fasth, 2 males, 3 females (alcohol) (UMSP); Rio Jaba at rock quarry, 1.4 km (air) W Las Cruces, 8°47.400'N, 82°58.200'W, el 1150 m, 15.iii.1991, Holzenthal, Muñoz, Huisman, 1 male, 5 females (alcohol) (UMSP); Parque Nacional Corcovado, Est. Sirena, Río Camaronal, 8° 28.860N, 83°35.640'W, el 5 m, 12-13.iv.1989, Holzenthal & Blahnik, 1 male (alcohol) (UMSP); San José: same data as holotype, 15 males, 5 females (pinned) (UMSP); Res. Biol. Carara, Río del Sur, 1.5 km (rd) S Carara, 9°46.140'N, 84°31.860'W, el 160 m, 13.iii.1991, Holzenthal, Muñoz, Huisman, 3 males (pinned), 6 males, 6 females (alcohol) (UMSP); Res. Biol. Carara, Río Carara in Carara, 9°46.680'N, 84°31.860'W, el 200 m, 14.iii.1991, Holzenthal, Muñoz, Huisman, 12 males, 12 females (alcohol) (UMSP); Río Negro, 3.5 km SE jct. route 239, 9°40.800'N, 84°23.640'W, el 230 m, 21.iii.1986, Holzenthal & Fasth, 3 males, 1 female (pinned), 8 males, 11 females (alcohol) (UMSP); PANAMA: San Blas: Que brada Pingadi, 9 km N Nusaganda, 1-2.iii.1995, Flint & Louton, 6 males, 5 females (pinned), 1 male, 3 females (alcohol) (NMNH); COLOMBIA: Antioquia: Quebrada Honda, 12 km SW Fredonia, el 1450 m, 22.ii.1983, O. S. Flint, Jr., 1 male, 1 female (pinned) (NMNH); Magdalena: Municipio de Santa Marta, Río Minca en Minca, 11°8.584'N, 74°6.967'W, el 570 m, 9.xii.1997, F. Muñoz-Q, et al., 2 males (pinned) (UMSP); Tolima: Armero nr. Guayabal, 2-10.ii.1977, E.L. Peyton, 28 males, 7 females (alcohol); ECUADOR: Cotopaxi: Quevedo, 36 km NE, el 305 m, 21.vii.1976, J. Cohen, 4 males, 3 females (alcohol) (NMNH); Guayas: Sta. Elena, 47.6 km N, el 37 m., 14.vii.1975, J. Cohen, 1 male (alcohol) (NMNH); Napo: Pano, el 580 m, 12.ix.1990, O. S. Flint, Jr., 1 male, 2 females (pinned) (NMNH); VENEZUELA: Sucre: Río Cocollar, 1.5 km SE Las Piedras de Cocollar, 10°09.617'N, 63°47.605'W, el 810 m, 7-8.iv.1995, Holzenthal & Flint, 2 males (pinned) (UMSP) (NMNH); Zulia: Río Yasa, ca. 3 km (air) E Kasmera (Est. Biológica), 9°56.460'N, 72°43.200'W, el 150 m, 14.i.1994, Holzenthal, Cressa, Rincón, 3 males, 1 female (pinned), 2 males, 4 females (alcohol) (UMSP) (IZAM); Caño Carichuano, 3.4 km SE Carbones del Guasare, 11°0.120'N, 72°17.100'W, el 70 m, 12-13.i.1994, Holzenthal, Cressa, Rincón, 2 males (pinned) (UMSP); Parque Nacional Perijá, Río Negro in Toromo, 10°3.060'N, 72°42.720'W, el 360 m, 15.i.1994, Holzenthal, Cressa, Rincón, 1 male, 1 female (pinned), 1 male, 1 female (alcohol) (UMSP); TRINIDAD: Arima River, Verdant Vale, 10°41'N, 61°18' W, el 170 m, 19.vi.1993, N.E. Adams & W.N. Mathis, 6 males, 1 female (pinned), 11 females (alcohol) (NMNH); Yarra River, Filette (1km SE), 10°47'N, 61°21'W, 25.vi.1991, O.S. Flint, Jr., 6 males (pinned) (NMNH); Blue Basin Waterfall, 10°44'N, 61°32'W, el 120 m, 21.vi.1993, 5 males, 1 female (pinned), 2 males, 3 females (alcohol) (NMNH); Blue Basin River, 10°44'N, 61°32'W, el 100 m, 21.vi.1993, N.E. Adams & W.N. Mathis, 2 males, 12 females (alcohol) (NMNH); Tacarigua River, Caura Rec. area, 10°43'N, 61°17'W, 22.vi.1993, O.S. Flint & N.E. Adams, 2 males, 3 females (pinned), 4 males, 7 females (alcohol) (NMNH); below Maracas Falls, 10°44'N, 61°24'W, el 250 m, 18.vi.1993, N.E. Adams & W.N. Mathis, 1 female (pinned) (NMNH); GUYANA: Kumu, 25 km SE Lethem, 3°15.9'N, 59°43.6'W, 4-5.iv.1994, O.S. Flint, Jr., 1 male (pinned) (NMNH).

Additional material examined.

COSTA RICA: San José: Res. Biol. Carara, Río del Sur, 1.5 km (rd) S of Carara, 9°46.140'N, 84°31.860'W, el 160 m, 13.iii.1991, Holzenthal, Muñoz, Huisman, 16 males, 12 females (pinned) (UMSP). These specimens are somewhat intermediate with Oecetis mexicana , as discussed above, and it is possible that they have been misassigned.

Etymology.

This species is named Oecetis constricta because of the constricted apex of the phallobase in this species.

Remarks.

The series listed above as additional material examined and discussed in the diagnosis was from Carara in Costa Rica, near where other specimens typical of Oecetis constricta were found. It is possible that this population owes its intermediacy in genitalic characters to some degree of introgression from Oecetis mexicana . An alternate explanation for this intermediacy could be method of clearing that was used on these specimens. They were cleared by use of the lactic acid method in the later part of the study; the heat used in this method may have introduced some degree of distortion to the apex of the phallobase (causing it to appear U-shaped, rather than distinctly pinched or constricted). This was never a factor in the many specimens of Oecetis constricta or Oecetis mexicana cleared with cold (room temperature) KOH.