Species composition and heterogeneity of blowflies assemblages (Diptera: Calliphoridae) in urban–rural gradients at regional scale in Argentinean Patagonia

Abstract

This work is aimed at describing the spatial distribution of Calliphoridae species along urban–rural gradients in the southern Patagonian steppe, and the influence of geographical factors on species composition and relative abundance. Blowfly assemblages from 12 localities of Santa Cruz and Tierra del Fuego, Argentina between 1997 and 2007 were studied. Samples were assigned to three categories of sites (wild sites, mid-urbanized and urbanized) and four environmental variables were recorded. Three dominant species account for 98% of all specimens, the wild Compsomyiops fulvicrura, and two synanthropic species: Lucilia sericata and Calliphora vicina. Additionally we tested the homogenization of urban calliphorid fauna by comparing the turnover of species among sites, but our findings showed similar heterogeneity of urban and non-urban assemblages.

El objetivo de este trabajo fue describir la distribución espacial de las Calliphoridae presentes en gradientes urbano-rurales de la estepa Patagónica austral, y la influencia de factores geográficos sobre su composición y abundancia relativa. Se registró la composición de califóridos en 12 localidades de Santa Cruz y Tierra del Fuego, Argentina entre 1997 y 2007. Las muestras fueron asignadas a tres categorías de sitio (urbano, semi-urbano y no habitados) y se registraron cuatro variables ambientales. Tres especies dominantes acumularon el 98% del total capturado de especimenes, la asinantrópica Compsomyiops fulvicrura, y dos especies sinantrópicas: Lucilia sericata y Calliphora vicina. Adicionalmente se puso a prueba la homogenización de la fauna de callifóridos urbana, mediante la comparación del recambio de especies entre sitios, pero nuestros resultados indicaron una similar heterogeneidad de las comunidades urbanas y no urbanas.

Keywords:

• Argentina
• Calliphoridae
• diversity
• Patagonia

Acknowledgements

We thank María Elena García for her valuable logistical support during the field work. We also thank Ariel Richard, Bernardo Mazzoni, Dante Ardenghi, Julio Nudelmann, Roberto Petrusic, Santiago Ansín, Alberto San Pedro and the personnel of Puesto Sanitario de El Chaltén for their cooperation during the field work. Finally, we gratefully acknowledge Greg Dahlem for his appropriate suggestions on an earlier draft of this manuscript. This work was supported by CONICET (PIA #7271 and PIP #02008) grants.