PROC. BIOL. SOC. WASH. 104(3), 1991, pp. 474-492 STUDIES OF NEOTROPICAL CADDISFLIES, XLVI: THE TRICHOPTERA OF THE RIO MOCHE BASIN, DEPARTMENT OF LA LIBERTAD, PERU Oliver S. Flint, Jr. and Luis Reyes A.^ Abstract. —Twenty-four species are recorded from the Rio Moche (primarily) and Rio Saiia basins of northwestern Peru. The climatological, chemical, and life zone characteristics of the Rio Moche are discussed. Six species are de-scribed as new: Chimarra (C.) dolabrifera, C. (Curgia) otuzcoensis, Smicridea {Rhyacophylax) bidactyla, Hydroptila sicilicula, Neotrichia riparia, and Triae-nodes peruanus. The trichopterous fauna of this region is basically one of wide-spread species, some known from the U.S.A. to Chile. The trichopterous fauna of Peru, the third largest country in South America, is very poorly known. There have been very few studies dealing exclusively with Peru, and these are limited to very restricted portions (Martynov 1912; Roback 1966; Hint 1975, 1980), thus most Peruvian records are scat-tered throughout the literature. Reyes has compiled a list of 1 07 species recorded from Peru (including those newly reported in this paper), which is certainly but a small frac-tion of the number of species that must oc-cur there. Essentially nothing has been re-corded from the coastal and immediately adjacent montane zones of northern Peru. This is the first report on the Trichopterous fauna that may be expected in other such suitable sites in these dry regions of western South America. Material on which this study is based is deposited in the National Mu-seum of Natural History (NMNH), Wash-ington and the Museo de Historia Natural "Javier Prado," Lima, Peru. Rio Moche Basin The Rio Moche basin is wholly located in the Department of La Libertad on the northwestern coast of Peru, the river enter-' Please see postscript. ing the Pacific Ocean just south of Trujillo, its capital (Fig. 1). The drainage basin is about 96 km deep, widening to about 25 km at the ocean, and covering 2708 square km. It is situated between parallels 7°46' and 8°15' South and between meridians 7 8° 16' and 79°08' West. The river itself is 102 km long with an average gradient of 4% (this and the follow-ing information is extracted primarily from Anonymous 1973, 1987). Its origin is in the Laguna Grande at 3988 m elevation, near the town of Quiruvilca in the Province of Santiago de Chuco, from which it flows through the Provinces of Otuzco and Tru-jillo (Fig. 2). Just below the town of Simbal, at 576 m, it is joined by the Rio Sinsicap, which originates above the village of Sin-sicap at over 3000 m. Most of the collec-tions were made in the portion of the Rio Sinsicap between Simbal and the junction with the Rio Moche. This section of the river is called by local inhabitants the Rio Lucumar (Figs. 3, 4) and it divides into sev-eral arms, which reunite near the village of Cumbray at which point it takes the name of Cumbray Creek (Figs. 5, 6) and serves as the laundry area for the small village. The rains in the basin are concentrated from January to April, with the driest pe-riod from June to September. The average
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