Abstract

SCHEIBLER, Erica E.; POZO, Viviana  and  PAGGI, Analia C.. Spatial and temporal distribution of larvae of Chironomidae (Diptera) in an Andean stream (Uspallata, Mendoza, Argentina). Rev. Soc. Entomol. Argent. [online]. 2008, vol.67, n.3-4, pp.45-58. ISSN 0373-5680.

A study was conducted on the larval composition of the family Chironomidae in an Andean stream in Uspallata locality (Mendoza, Argentina). Seasonal samplings were performed over a full annual cycle (2001/2002) at three sites, along an altitudinal gradient. Physical and chemical variables were measured in both the field and the laboratory. Relationship between presence and abundance of chironomids and environmental parameters was explored using a Canonical Correspondence analysis. Seven genera were identified, corresponding to four subfamilies: Chironominae, Orthocladiinae, Podonominae and Tanypodinae. The subfamily Orthocladiinae had the highest genus richness (Cricotopus van der Wulp, Onconeura Andersen & Saether and Parametriocnemus Goetghebuer), density and frequency of occurrence at seasonal and spatial levels. Podonominae (Podonomus Philippi and Podonomopsis Brundin) was found only at SA, whereas Chironominae (Polypedilum Kieffer) was present at UD. Tanypodinae (Pentaneura Philippi) was found at all three sampling sites, although in lower density. Increased conductivity and water temperature and decreased substrate size were detected from SA to UD, coinciding with the disappearance of Podonomus and Podonomopsis and the appearance of Polypedilum toward UD. This study leads to the conclusion that the system presents low genus richness compared to other mountain systems of Argentina.

Keywords : Chironomidae distribution; Spatial and temporal variations; Density; Generic richness.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )