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Abstract. Odonata is known to be sensitive to structural habitat quality and is a valuable tool to evaluate landscape degradation. This study determined the species diversity of Odonata in Buru-un, Iligan City and Tubod, Lanao del Norte, Philippines. Eight sites were assessed on August 27 - 31, 2012 and on October 26 - 30, 2012 for a total of 98 man-hours. Sweep nets were used for collection. Twenty six species were identified from all sampling sites. Lake Babuyan (Site 4) and Kalilangan Spring (Site 5) had the highest species richness. Trithemis aurora, an oriental species, was the most abundant species. Moderate species diversity was recorded with low endemism (35 %).
Key Words: Species diversity, endemism, habitat, richness, Trithemis aurora.
Introduction. Biodiversity loss is a global phenomenon. Its impact may be greatest in the tropics where majority of species are distributed. This long-recognized pattern of increasing diversity towards the tropics is exemplified in tropical forests, which take up less than two percent of the Earth's surface, but contain upwards of fifty percent of its biodiversity (Collen et al 2008). Lack of information about the habitat conditions impedes conservation planning in other types of freshwater system and relates equally to focal species that are neither large nor wide-ranging (Abell 2002).
The insect order Odonata (dragonflies and damselflies) includes some of the most ancient and beautiful insects that ever roamed the Earth. It also includes some of the largest flying invertebrates ever to have lived. Approximately 6,000 species and subspecies belonging to 630 genera and 28 families are known all over the world (Sharma et al 2007). Dragonflies and damselflies are well-known invertebrates and are of great value because of their ecological importance. The Odonata comprises a significant animal component of aquatic environments (DiSalvo et al 2003). Odonata is well studied and conserved for it is highly valued, being iconic, aesthetic, and sensitive biological indicators of landscape change. Species of Odonata are both important subjects in their own right as well as important role players in overall biodiversity conservation (Samways 2008).
Odonata is sensitive to habitat structure and is an excellent indicator of changes in habitat structure (Clausnitzer 2004). The group constitutes a valuable tool for various types of bio-assessment and bio-monitoring of aquatic habitats which include...