A new species of Smicridea from Argentina (Trichoptera: Hydropsychidae)

Una especie nueva de Smicridea de la Argentina (Trichoptera: Hydropsychidae)

Sganga, Julieta V.

Laboratorio de Entomología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. C1428EHA, Buenos Aires, Argentina; e-mail: jsganga@bg.fcen.uba.ar

RESUMEN. Se describen el macho y la hembra de una especie nueva de Smicridea (Rhyacophylax) Müller (Hydropsychidae: Smicrideinae), recolectados cerca del Parque Nacional El Palmar, provincia de Entre Ríos, Argentina. Los machos se caracterizan por la presencia de tres puntas en el ápice del falo, una dorsal y dos laterales, y dos ganchos internos. La hembras se distinguen fácilmente por las características de la vagina y de la placa interna.

PALABRAS CLAVE. Hydropsychidae. Smicridea. Especie nueva. Neotropical.

ABSTRACT. The male and the female of a new species of Smicridea (Rhyacophylax) Müller (Hydropsychidae: Smicrideinae) collected near by El Palmar National Park, Entre Ríos Province, Argentina, are described. The males of this species are characterized by the presence of three points at the apex of the phallus, one dorsal and two lateral, and two lateral internal hooks. The females are easily distinguished by the characteristics of the vagina and the internal plate.

KEY WORDS. Hydropsychidae. Smicridea. New species. Neotropical.

INTRODUCTION

Smicridea McLachlan is the only genus of Smicrideinae present in the Neotropical region (Schefter, 1996), where it is both abundant and diverse.

The species of this genus are grouped in two subgenera, Smicridea (Smicridea) McLachlan and Smicridea (Rhyacophylax) Müller, which are found from southwestern United States, through Central and South America and the Antillean islands (Flint et al., 1999).

The adults of both subgenera may be distinguished by their wing venation, tibial formula (Flint, 1974), and the presence of two pairs of pheromonal glands in the abdominal segments VI and VII of Smicridea (Smicridea), that are absent in the abdomen of Smicridea (Rhyacophylax) (Flint & Denning, 1989).

In Argentina, the knowledge of the diversity of Smicridea is due almost exclusively, to the work of Flint (1972, 1973, 1978, 1980, 1982, 1983, 1989), who has described 25 of the 33 species of the genus recorded from this country. Twenty three of these 33 species, belong to the subgenus S. (Rhyacophylax), and 10 to the subgenus S. (Smicridea). The species of both subgenera extend their distribution from the Jujuy Province (in the north of Argentina) to the Chubut Province (in Patagonia) (Table 1).

Table 1 . Distribution of the species of Smicridea recorded from Argentina.

The knowledge of the females of Smicridea is poor. Only the females of 52 of the 171 Neotropical species of the genus have been described (Flint, 1964, 1968a y b, 1974, 1981, 1989; Kumanski, 1987; Botosaneanu, 1990, 1994; Blahnik, 1995; Holzenthal & Blahnik, 1995), about a third of the total. From Argentina, the females of Smicridea (Smicridea) annulicornis (Blanchard), Smicridea (Smicridea) anticura Flint, Smicridea (Smicridea) decora (Navás), Smicridea (Smicridea) frequens (Navás), Smicridea (Smicridea) mucronata Flint, Smicridea (Rhyacophylax) murina McLachlan, and Smicridea (Smicridea) pucara Flint have been described.

MATERIAL AND METHODS

The males and females of the new species were collected with a net in the marginal vegetation of El Palmar Stream, near El Palmar National Park, Entre Rios Province, Argentina, and preserved in alcohol.

The disected parts of the specimens were cleared in NaOH 10%, neutralized with phenol, dyed with acid fuchsine when necessary, and mounted in glycerin or Fauré media for microscopical observations.

The types of the new species are deposited at the Museo Argentino de Ciencias Naturales, Buenos Aires.

RESULTS

Smicridea (Rhyacophylax) palmar sp.nov.

(Figs. 1-7)

Etymology. Named for the place where the specimens were collected.

Type Material. Male holotype and 8 paratypes (6 males and 2 females): Argentina, Entre Ríos, arroyo El Palmar, Ruta Nacional 14, Angrisano col., XI-2003.

Diagnosis. This species is readly identified by the structure of the male genitalia. The distal part of the phallus that bears three retrorse points at the apex, one dorsal and two lateral, and two lateral internal hooks, is diagnostic.

Description

Male (Figs. 1-3)

Length of forewing. 4.2 to 5.0 mm.

Coloration of the body dark grayish brown. The specimens preserved in alcohol acquire a dark reddish brown coloration, which contrasts with that of the setal warts and the abdominal sterna that become whitish. Forewing dark brown, with a transverse, subapical, irregular, white band, and two pale maculae, a round one between R 4 and R 5, and a subrectangular one anterior to R 2+3 and the proximal part of R 2, covering a zone of Sc and R 1.

Width of eye, in dorsal view, almost half of the interocular distance. Anterolateral process of fifth sternum as long as the segment.

Genitalia. Antero-lateral margin of the ninth segment rounded, and produced anteriorly (Fig. 1). Tenth tergite, in lateral view, subtriangular, dorsal margin slightly concave, posterodorsal corner slightly curved and directed dorsally; in dorsal view (Fig. 3), subtriangular, apex pointed and slightly produced. Inferior appendages two segmented, almost parallel-sided, with the basal portion long (almost three times length of apical segment), broadening distally, and the apical portion ending in a point. The basal part of the phallus broadens proximally, forming an angle of about 90 º with the distal part, which is tubular and bears three retrorse points at the apex, one dorsal and two lateral (one on either side), and two lateral internal hooks that become basal as the internal sclerite is exserted (Figs. 1-2). Internal sclerite long and slender, sinuous in lateral view.

Female (Figs. 4-7)

Length of forewing. 5.2 mm.

Eighth sternum formed by two trapezoidal sclerites, with the posterior margin straight, the medial-posterior angle rounded, and the lateral-posterior one enlarged; with short setae covering the surface of the sternum, and longer setae along the posterior margin (Fig. 4). Ninth tergite, in dorsal view, with the apex almost straight, and bearing long setae along the lateral margins (Fig. 5). Internal plate, in dorsal-posterior view, U-shaped with the lateral arms arched towards the centre, and the anterior bridge straight, produced laterally (Fig. 6). Vagina complex, as in Fig. 7.

Immature stages. Unknown.

Systematic considerations. On the basis of the structure of the male genitalia, and especially for the presence of three points at the tip of the phallus, Smicridea (Rhyacophylax) palmar sp.nov. seems to be related to Smicridea (Rhyacophylax) argentina (Navás, 1920). They are easily distinguished by the position of the points, which are dorsal in S. (R.) argentina, and one dorsal and two lateral in Smicridea (Rhyacophylax) palmar sp. nov., and by the presence of two lateral internal hooks in Smicridea. (Rhyacophylax) palmar sp. nov. which are absent in Smicridea (Rhyacophylax) argentina.

Figures 1-7. Smicridea (Rhyacophylax) palmar Sganga sp.nov. 1-3: male genitalia. 1, lateral view. 2, apex of the phallus, dorsal view. 3, terga IX, X and inferior appendages, dorsal view. 4-7: female genitalia. 4, lateral view. 5, dorsal view. 6, internal plate, postero-dorsal view. 7, vagina, ventral view.

ACKNOWLEDGEMENTS

I warmly thank Dr. Elisa Angrisano (Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires) for her helpful comments on the manuscript and for her endless patience, and Dr. Axel Bachmann (Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires) for his comments on the manuscript.

LITERATURE CITED

1. BLAHNIK, R. 1995. New species of Smicridea (subgenus Smicridea) from Costa Rica, with a revision of the fasciatella complex (Trichoptera: Hydropsychidae). J. N. Am. Benthol. Soc. 14(1): 84-107.         [ Links ]
2. BOTOSANEANU, L. 1990. Results of a trichopterological (Insecta: Trichoptera) travel to the Lesser Antilles in 1989. Bull. Inst. Roy. Sci. Nat. Belgique, Entom 60: 39-48.         [ Links ]
3. BOTOSANEANU, L. 1994. Les Trichoptères de la Guadeloupe. Ann. Soc. Entom. France (NS)30: 33-54.         [ Links ]
4. FLINT, O.S. 1964. The caddisflies (Trichoptera) of Puerto Rico. Univ. Puerto Rico. Agr Exper Stat, Techn Paper 40: 1-80.         [ Links ]
5. FLINT, O.S. 1968a. The caddisflies of Jamaica (Trichoptera). Bull. Inst. Jamaica, Sci Ser 19: 1-68.         [ Links ]
6. FLINT, O.S. 1968b. Bredin- Archbold- Smithsonian Biological Survey of Dominica, 9. The Trichoptera (Caddisflies) of the Lesser Antilles. Proc. U S Nat. Mus. 125(3665): 1-86.         [ Links ]
7. FLINT, O.S. 1972. Studies of Neotropical caddisflies XIV: on a collection from northern Argentina. Proc. Biol. Soc. Wash. 85: 223-248.         [ Links ]
8. FLINT, O.S. 1973. A replacement name for Smicridea (R.) minima Flint (Trichoptera: Hydropsychidae). Proc. Biol. Soc. Wash. 75:219.         [ Links ]
9. FLINT, O.S. 1974. Studies of Neotropical caddisflies, XVII: The genus Smicridea from North and Central America (Trichoptera, Hydropsychidae). Smith. Contr. Zool. 167: 1-65.         [ Links ]
10. FLINT, O.S. 1978. Studies of Neotropical caddisflies, XXII: Hydropsychidae of the Amazon basin (Trichoptera). Amazoniana 6:373-421.         [ Links ]
11. FLINT, O.S. 1980. Studies of Neotropical caddisflies, XXVI: new species from Argentina (Trichoptera). Rev. Soc. Entomol. Arg. 39: 137-142.         [ Links ]
12. FLINT, O.S. 1981. Studies of Neotropical caddisflies, XXVIII. The Trichoptera of the Río Limón basin, Venezuela. Smith. Contr. Zool. 330: 1-60.         [ Links ]
13. FLINT, O.S. 1982. Trichoptera of the Area Platense. Biol. Acuát. 2:1-70.         [ Links ]
14. FLINT, O.S. 1983. Studies of Neotropical caddisflies, XXXIII: new species from austral South America (Trichoptera). Smith. Contr. Zool. 377: 1-100.         [ Links ]
15. FLINT, O.S. 1989. Studies of Neotropical caddisflies, XXXIX: the genus Smicridea in the Chilean Subregion (Trichoptera: Hydropsychidae). Smith. Contr. Zool. 472: 1-45.         [ Links ]
16. FLINT, O.S. & D.G. DENNING. 1989. Studies of Neotropical caddisflies, XL: new species of Smicridea (Smicridea) from Middle America and the West Indies (Trichoptera: Hydropsychidae). Proc. Biol. Soc. Wash. 102(2): 418-433.         [ Links ]
17. FLINT, O.S. Jr., R.W. HOLZENTHAL & S.C. HARRIS. 1999. Catalog of the Neotropical Caddisflies (Insecta: Trichoptera). Ohio Biol. Survey, Columbus, Ohio.         [ Links ]
18. HOLZENTHAL, R.W. & R.J. BLAHNIK. 1995. New species of Smicridea (Rhyacophylax) (Trichoptera: Hydropsychidae), from Costa Rica. Entom. News 106: 213-223.         [ Links ]
19. KUMANSKI, K.P. 1987. On the Caddisflies (Trichoptera) of Cuba. Acta Zool Bulgarica 34: 3-35.         [ Links ]
20. NAVÁS, R.P.L. 1920. Insectos Sudamericanos (1ª, 2ª y 3ª serie). An. Soc. Cient. Arg. 90: 33-72.         [ Links ]
21. SCHEFTER, P.W. 1996. Phylogenetic relationships among subfamily groups in the Hydropsychidae (Trichoptera) with diagnoses of the Smicrideinae, new status, and the Hydropsychinae. J.N. Am. Benthol. Soc. 15(4): 615-633.         [ Links ]

Recibido: 25-XI-2004
Aceptado: 24-XI-2005