<span name="style_bold">Feeding habits of immature individuals of Ephemeroptera, Plecoptera, and Trichoptera from middle reaches of a tropical mountain stream.</span> Morphological and behavioral aspects of insects allow their grouping in trophic guilds and represent their dependence on food resources. We determined the feeding habits of immature organisms of Ephemeroptera, Plecoptera, and Trichoptera (EPT) from the middle reaches of Gaira stream (Sierra Nevada de Santa Marta, Colombia), using gut content analysis. We identified 13 EPT genera, but only ten were analyzed for a total of 100 organisms. We describe six food items: animal parts (AP), vascular plant tissue (VPT), microalgae (M), fungi (F), coarse particulate organic matter (CPOM) and fine particulate organic matter (FPOM). Baetodes was determined to be a collector-scraper, since FPOM represented 46.6% of food content, followed by F (38.4%). <span name="style_italic">Chimarra, Leptohyphes</span>, <span name="style_italic">Lachlania</span>, and <span name="style_italic">Thraulodes</span> were categorized as collectors with average proportions of FPOM 86.8%, 93.1%, 93.1% and 93.7%, respectively. <span name="style_italic">Phylloicus, Smicridea</span> and <span name="style_italic">Leptonema</span> were main consumers of VPT and CPOM with proportions of 76.3%, 54.6%, and 62.4%, respectively; while ratios of FPOM were 22.3%, 38.8%, and 32.9%, respectively. While all are detritivores, <span name="style_italic">Phylloicus</span> is functionally classified as shredders and <span name="style_italic">Smicridea</span> and <span name="style_italic">Leptonema</span> as collectors. <span name="style_italic">Atopsyche</span> and <span name="style_italic">Anacroneuria</span> were the only taxa in which AP were observed in high proportions, 57.9% and 58.2%, respectively, for that reason they were classified as predators. The organisms examined consume a wide variability of resources. Rev. Biol. Trop. 62 (Suppl. 2): 169-178. Epub 2014 April 01. were the only taxa in which AP were observed in high proportions, 57.9% and 58.2%, respectively, for that reason they were classified as predators. The organisms examined consume a wide variability of resources. Rev. Biol. Trop. 62 (Suppl. 2): 169-178. Epub 2014 April 01.

insectos acuáticos; contenido estomacal; ítem alimentario; grupos tróficos; río Gaira