Insects associated to ephemeral pools in Huentelauquén (29ºS Coquimbo Region, Chile).

J Pizarro-Araya,P De Los Ríos-Escalante,F.M Alfaro

doi:10.1590/1519-6984.254095

Abstract

In northern central Chile, ephemeral pools constitute shallow isolated water bodies with a favourable habitat for fauna adapted to seasonal changes. Based on the limited knowledge about the fauna-particularly insects-associated to these ecosystems, the objective of this study was to characterize the richness, composition, structure and similarity of the insect communities associated with ephemeral pools in Huentelauquén (29º S, Coquimbo Region, Chile). By using pitfall traps, 10,762 individuals were captured, represented by 7 orders, 27 families, and 51 species. Coleoptera and Hymenoptera were the best represented orders, with Neuroptera, Orthoptera and Plecoptera being poorly represented groups. The non-parametric estimators evaluated showed wealth values above those observed for all the studied pools, and their accumulation curves suggest the existence of an incomplete species inventory in the studied community. Additionally, the hierarchical and ordering analysis showed groupings of pools located in the northwest and southeast of Huentelauquén. Preliminarily we found a negative correlation between the area of the pools and the richness (species) and abundance of insects. Additional studies (on other arthropod groups and other seasons of the year) could provide a better understanding of the local processes of extinction and colonization of the species inhabiting these fragile coastal environments.

Highlights

The coastal areas of northern Chile have different ecological and geomorphological zones (Abreu and Bannon, 1993; Villagrán, 2001; Smith-Ramírez et al, 2005) that support a wide variety of habitats conditioned by the maritime influence and aridity (Ormazábal, 1993; Gajardo, 1993)
The highest species richness was found in the two and seven pool, both with 24 species, whereas the lowest value was observed in the fifth pool, with 13 species (Figure 3)
The insect assemblage associated to ephemeral pools included native species that are widely distributed in the Chilean coastal desert, such as Camponotus morosus (Formicidae), a native species with wide distribution in sclerophyllous shrubs in central Chile and generalist feeding behaviour (Snelling and Hunt, 1975; Grez et al, 1986); and Gyriosomus foveopunctatus (Tenebrionidae), a darkling beetle typical from inner steppe shrubs (PizarroAraya and Jerez, 2004)

Summary

Introduction

The coastal areas of northern Chile have different ecological and geomorphological zones (Abreu and Bannon, 1993; Villagrán, 2001; Smith-Ramírez et al, 2005) that support a wide variety of habitats conditioned by the maritime influence and aridity (Ormazábal, 1993; Gajardo, 1993). In these areas there have been relict zones with biotic components from the Tertiary period, which have affected species distribution and favoured the emergence. As a result of its latitudinal position, the coastal area of Central Chile is affected by the ENSO phenomenon (El Niño Southern Oscillation) (Romero and Garrido, 1985; Cepeda-Pizarro et al, 2005a, b), as well as by the potential effects of global climate change (Schlesinger and Mitchell, 1987; Mooney et al, 2001)

Objectives

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Results

Conclusion