Review and redescription of species in the Oecetis avara group, with the description of 15 new species (Trichoptera, Leptoceridae)
Author
Blahnik, Roger J.
Author
Holzenthal, Ralph W.
text
ZooKeys
2014
376
1
83
http://dx.doi.org/10.3897/zookeys.376.6047
journal article
http://dx.doi.org/10.3897/zookeys.376.6047
1313-2970-376-1
2B58574A5FCF40D19A3AFB4D13D33A92
2B58574A5FCF40D19A3AFB4D13D33A92
Oecetis angularis
sp. n.
Figs 3, 33, 47, Map 1
Diagnosis.
Oecetis angularis
sp. n. is diagnosed by its intermediate size, coloration (yellow, with distinct forewing spots), weakly protruding, but angularly demarcated ventral lobe of the inferior appendage (Fig. 3A), and by having a phallobase with its ventral apex acutely angled (V-shaped), as viewed caudally (Fig. 3C). The ventral margin of the phallobase is arched rather than strongly bent, as viewed laterally. Other species in which the apex of the phallobase is V-shaped in caudal view include
Oecetis metlacensis
,
Oecetis uncata
sp. n., and
Oecetis apache
sp. n., all of which are slightly larger in size, darker in color (yellowish-brown or light brown), and have the phallobase more strongly arched or bent as viewed laterally, and
Oecetis acciptrina
, which is much smaller in size and has the phallobase very strongly bent or hooked near its apex as viewed laterally.
Oecetis metlacensis
and
Oecetis apache
additionally differ by having much less prominent forewing spots (absent in
Oecetis apache
).
Despite
the resemblance of the genitalia to the above mentioned species, in overall appearance (size, color and forewing spotting)
Oecetis angularis
probably more closely resembles
Oecetis protrusa
sp. n.,
Oecetis tumida
sp. n., or
Oecetis mexicana
, sp. n., all of which differ in having the apex of the phallobase U-shaped in caudal view (although the shape of the apex may be somewhat difficult to discern in
Oecetis tumida
due to its bulbous expansion). A distinction can be made on the basis that the ventral margin of the phallobase is not
"keeled"
preapically in species described as having a U-shaped apex. The general shape of the inferior appendage in
Oecetis angularis
, with a weakly protruding ventral lobe, is most similar to
Oecetis tumida
, which is also similar in size;
Oecetis tumida
differs in having the ventral margin the phallobase noticeably convexly rounded preapically, as viewed laterally (Fig. 24B), somewhat as in
Oecetis protrusa
. In Costa Rica, where
Oecetis angularis
and
Oecetis protrusa
have been found together,
Oecetis angularis
is generally somewhat larger in size than
Oecetis protrusa
. In other parts of their ranges, however, size differences seem to be less apparent.
In size, color, and forewing spotting
Oecetis angularis
is also nearly identical to
Oecetis punctata
, with which it may co-occur. However, the differences in the shape of the inferior appendages of the males, as well as the arrangement of the crossveins of the chord, as discussed above for characters separating the
Oecetis avara
and
Oecetis punctata
groups, should readily distinguish them.
Adult.
Forewing length: male (9.3-10.8 mm); female (6.3-9.0 mm). Color pale yellowish to brownish-yellow (similar to
Oecetis
mexicana
); forewing spots distinct, spots at base of discal and thyridial cells large or moderately large, other spots smaller; veins of forewing chord widely spaced, s and r-m veins slightly closer; chord with small spots at juncture of major veins, spots at opposite ends of chord larger; spots at apices of major veins small, pigmentation confined to vein. Setae along veins in apical part of forewing elongate, semi-prostrate, laterally diverging. Fringe of setae along costal margin of forewing moderate in length, somewhat projecting, not conspicuously erect.
Male genitalia.
Segment IX very short, with elongate setae along posterolateral margin. Preanal appendage moderately elongate, simple in structure, apical setae more elongate. Tergum X with elongate, narrow, deflexed mesal lobe, apex of lobe slightly enlarged, with numerous small sensilla; mesal lobe continuous basoventrally with short, paired lateral membranous or lightly sclerotized projections. Inferior appendage with prominent rounded dorsal process and angularly projecting ventral process; ventral process not strongly projecting, forming an approximate right angle with dorsal process; basomesal projection rounded, moderately prominent, with short, stout mesally directed setae; dorsal process with stout, ventrally curved setae; base of appendage, as viewed ventrally (Fig. 3E), distinctly angled. Phallobase short and tubular basally, with relatively elongate, arched ventral apex; apex, as viewed caudally, with ventral margin sharply V-shaped and slightly keeled (Fig. 3C); phallotremal sclerite elongate, prominent.
Figure 3.
Oecetis angularis
sp. n., male genitalia: A lateral B phallic apparatus, lateral C phallic apparatus, caudal D inferior appendage, caudal E inferior appendage, ventral.
Holotype.
Male(pinned), COSTA RICA: Puntarenas:
Rio
Bellavista, ca. 1.5 km NW Las Alturas,
8°57.060'N
,
82°50.760'W
, el 1400 m, 16-17.iii.1991, Holzenthal,
Munoz
, Huisman (UMSP) (UMSP000208089).
Paratypes.
GUATEMALA: Suchitepequez: Finca Moca, 12.vi.1966, Flint & Ortiz, 1 male, 1 female (pinned) (NMNH); Puente Ixtacapa, 18-19.vi.1966, Flint & Ortiz, 1 male (pinned)(NMNH); COSTA RICA: Arenal, Quebrada Trondorancito, 24.vii.1967, O. S. Flint, Jr., 13 males, 9 females (pinned) (NMNH); La Suiza, 17.vi.1967, Flint & Ortiz, 1 male (pinned) (NMNH);
Rio
Seco, NW Esparta, 28.vii.1967, O. S. Flint, Jr., 1 male (alcohol) (NMNH); Alajuela: Reserva Forestal San Ramon,
Rio
San Lorencito and tribs.,
10°12.960'N
,
84°36.420'W
, el 980 m, 30.iii.-1.iv.1987, Holzenthal, Hamilton, Heyn, 1 male (alcohol) (UMSP);
Rio
Pizote, ca. 5 km N Dos
Rios
,
10°56.880'N
,
85°17.460'W
, el 470 m, 9.iii.1986, Holzenthal & Fasth, 1 male (pinned), 16 males, 15 females (alcohol) (UMSP); Cartago:
Rio
Reventazon
in CATIE along Sendero Espaveles,
9°53.580'N
,
83°39.060'W
, el 500 m, 22.iii.1991,
Munoz
, 5 males, 2 females (pinned), 1 male (alcohol) (UMSP);
Limon
:
Rio
Banano, 16 km WSW Bomba,
9°52.280'N
,
83°10.020'W
, el 150 m, 26.iii.1987, Holzenthal, Hamilton, Heyn, 2 males, 2 females (pinned) (UMSP);
Rio
Telire and small trib., SE Suretka,
9°33.240'N
,
82°53.520'W
, el 48 m, 1.ii.1986, 1 male, 1 female (pinned) (UMSP); Res. Biol. Barbilla,
Rio
Dantas,
9°59.640'N
,
83°26.580'W
, el 300 m, 27-30.i.1992, Holzenthal,
Munoz
, Kjer, 7 males (alcohol) (UMSP); Puntarenas: same data as holotype, 15 males, 8 females (pinned) (UMSP);
Rio
Coton
in Las Alturas,
8°56.280'N
,
82°49.560'W
, el 1360 m, 18.iii.1991, Holzenthal
Munoz
, Huisman, 18 males, 7 females (pinned), 10 males, 18 females (alcohol) (UMSP); same location, 12.viii.1990, Holzenthal, Blahnik,
Munoz
, 7 males, 1 female (pinned), 8 males (alcohol) (UMSP);
Rio
Jaba, 2.4 km (air) NW San Vito,
8°49.920'N
,
82°59.460'W
, el 970 m, 13.vi.1986, Holzenthal, Heyn, Armitage, 1 male (pinned), 1 male, 1 female (alcohol) (UMSP);
Rio
Ceibo
, route 2, ca. 6 km W road to Buenos Aires,
9°8.940'N
,
83°22.620'W
, el 250 m, 20.ii.1986, Holzenthal, Morse, Fasth, 1 male (alcohol) (UMSP);
Rio
Singri, ca. 2 km (air) S Finca Helechales,
9°3.420'N
,
83°4.920'W
, el 720 m, 21.ii.1986, Holzenthal, Morse, Fasth, 10 males, 20 females (alcohol) (UMSP); ECUADOR: Cotopaxi: Latacunga, 133 km W, 2.vii.1975, el 1080 m, A. Langley & J. Cohen, 1 male (pinned) (NMNH); Quevedo, 36 km NE, el 335 m, 2.vii.1976, J. Cohen, 9 males, 4 females (alcohol) (NMNH); Loja:
Rio
Puyango, el 300 m, 17-18.viii.1977, L. E.
Pena
G., 2 males, 1 female (pinned) (NMNH); Pichincha: Santo Domingo de los Colorados, 14. km E, 5.vii.1975, Langley & Cohen, 1 male (pinned) (NMNH).
Etymology.
This species is named
Oecetis angularis
for the acutely angled ventral apex of the phallobase, as seen in caudal view.