The Erotylidae family comprises more than 280 genera and 3,500 speciesworldwide. They are the most diverse of the Cucujoidea, are brightly coloredand they eat mushrooms. In the Darién National Park, 14 genera are recognizedand 37 species in two subfamilies: Erotylinae and Tritominae. This work aimsto report the fungus with which immature and adult stages feed onScaphidomorphus bosci Guérin-Méneville beetle, 1841 in the Darién NationalPark. 12 field visits were made between the years 2013 to 2017 in the RanchoFrío Station, Province of Darién. We made three clearings of 2 km along thetrails inside the forest while surveying for decomposing wood trunks for thepresence of the beetle S. bosci. A total of 32 adults, 135 larvae and 128 pupaeof the beetle were collected, located on the substrate with the mushrooms.Samples were collected from the substrate (wood) where I found the fungusand they were moved to the laboratory, following the rules indicated by thepersonnel of the Laboratory of Microbiology and Parasitology, of the School of Biology of the University of Panama. The site was geo- referenced whilebiological and ecological data were taken where the beetles were located. Thefungus was isolated and identified as Trichoderma sp (Hypocreales,Hypocreaceae, Teleomorfo Hypocrea) that belongs to the Ascomycota division,present in almost all soils and grow on dead wood, bark, manure, other fungi,building materials and animals, including human beings, demonstrating greatpotential opportunity and adaptation to ecological conditions. In conclusion, thefungus-beetle relationship S. bosci could be a “weed fungus” which forms apart of the beetle’s diet, while also having a commensal type relationship withthe beetle and may be used as a supplemental source of food.