Graphical abstract Even though the triatomine Mepraia gajardoi doesn't coexist with the rodent Octodon degus, it is able to acquire and excrete Trypanosoma cruzi obtained from this mammal. Highlights • Mepraia gajardoi and Triatoma infestans acquire Trypanosoma cruzi from Octodon degus. • M. gajardoi detected 100% of infected O. degus whereas T. infestans only 50%. • M. gajardoi and T. infestans detect TcI, TcV and TcV (single and mixed infections). • M. gajardoi detected TcI in all infected O. degus and T. infestans only in 38%. • T. cruzi was more detectable by M. gajardoi at 40 and 120 days post xenodiagnoses. Abstract Chagas disease is a vector-borne disease caused by the parasite Trypanosoma cruzi , and transmitted by triatomine insects to several mammal species. In Chile, the wild triatomine species are the endemic Mepraia species, and the only domestic vector of Chagas disease is Triatoma infestans. The aim of this study was to determine the competence of M. gajardoi compared to T. infestans as a T. cruzi vector using the naturally infected rodent Octodon degus. M. gajardoi amplified T. cruzi present in all O. degus studied while T. infestans only in half of the infected rodents. Both triatomine species excrete metacyclic trypomastigotes and amplified the same three T. cruzi DTUs, however, M. gajardoi showed differences in their ability to amplify TcI. TcV and TcVI had the same probability to be amplified by both triatomine species. Both species amplified mixed infections, with TcI-TcVI as the most represented. This study reports the higher vector competence of M. gajardoi in comparison to T. infestans. [ABSTRACT FROM AUTHOR]