dcsimg

Comprehensive Description

provided by Smithsonian Contributions to Zoology
Smicridea (Smicridea) matancilla

The male genitalia of this species do not suggest a close relationship to any other known species of the genus. The curled, lateral spine near the apex of the phallus, the lateral and dorsal elongate lobes, and thin ventral projection, all are unique

ADULT.—Length of forewing, 5 mm. Uniformly pale gray, but completely denuded. Eye of male in frontal aspect with diameter 1/2 that of interocular distance. Anterolateral process of fifth sternum as long as sternum; with 2 pairs of internal sacs, each ∼3/4 the length of the segment in which it lies.

Male Genitalia: Ninth segment with anterior margin nearly vertical. Tenth tergum elongate; tergite slightly upturned in lateral aspect and produced posteriad in a small apicomesal lobe in dorsal aspect. Clasper with basal segment narrowing slightly basad; apical segment elongate, bluntly pointed. Phallus tubular, base at right angles to stem, basal opening about 4 times diameter of stem; subapically with a curled lateral spine whose base is enclosed in a shallow lateral pocket; apex with an elongate lateral plate concave mesally and a dorsolateral elongate lobe whose apex is knobbed, and a thin, transverse, ventral lip.

Female Genitalia: Unknown.

MATERIAL EXAMINED.—Holotype, male: CHILE: PCIA. CACHAPOAL: Cerro La Matancilla, Cordillera Costa, 1750 m, 8–10 Jan 1982, L.E. Peña G. Type NMNH.

Paratype: CHILE: PCIA. CACHAPOAL: Same data, 1 , (NMNH).

As discussed under “Genus Smicridea McLachlan” (and see Flint 1974a), the two subgenera are easily characterized in the adult stage, but not in their immature stages. The manner of separation of the veins R2+3 and R4+5 and the proximity of the the radiomedial system basally to the cubital system in the hindwing are sufficient for the recognition of the two subgenera. In addition, the males in Rhyacophylax lack the reticulate, internal sacs in the terminal abdominal segments that are present in the subgenus Smicridea. The males of Rhyacophylax lack the two preapical spurs on the hindlegs rather than having the full complement of four spurs as in the nominate subgenus.

The only species of subgenus Rhyacophylax known from the Chilean Subregion was placed in the magna species group (Flint 1974a). Now, with the synonymy of magna, this becomes the murina species group. The only other known species that shares the paired apicodorsal processes and lack of an apicoventral lobe on the phallus is S. (R.) appendiculata Flint, which is herein placed in the murina species group. These two species are mostly allopatric, with murina extending north to south along the Pacific Rim from Nicaragua to Chile, and appendiculata extending east and west from Brazil into Paraguay. An area of potential overlap exists along the eastern foothills of the Andes in Bolivia and northwestern Argentina.
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bibliographic citation
Flint, Oliver S., Jr. 1989. "Studies of Neotropical Caddiflies, XXXIX: The Genus Smicridea in the Chilean Subregion (Trichoptera: Hydropsychidae)." Smithsonian Contributions to Zoology. 1-45. https://doi.org/10.5479/si.00810282.472