A qualitative taxonomic insect survey and similarity analysis of streams in the Chihuahuan Desert of west Texas

A qualitative analysis of insects in permanent and temporary streams at the Dalquest Desert Research Site (DDRS) of the Chihuahuan Desert was conducted from October 2008 to January 2010.  Aquatic insect communities were cataloged and then compared using Sorensen’s similarity index.  A total of 16,755 aquatic insect specimens representing eight orders,  47 families, 109 genera, and 104 species were collected during this study.  The permanent streams, Los Alamos Ranch Spring (LARS) and Alamo Spring (AS), had a 74% similarity in taxa over the entire sampling period.  Alamo Spring had a 64.4% similarity to TempRock (the relatively temporary stream in this study); whereas, the similarity between LARS and TempRock was 63.1% during the sampling period.  This study contributes to our knowledge of species richness, documents range extensions, and poses questions of taxonomic interest concerning aquatic insects in desert streams in the Big Bend region of western Texas.