this is the first literature record of the genus stenomicra coquillett (diptera: periscelididae) from south america (neotropical region). new information on the biological cycle of stenomicra species in the wild is provided, and four species of the genus eryngium l. (apiaceae) are recorded as host plants for immature stages of this taxon. the specimens of stenomicra sp. were collected in sierra de la ventana, buenos aires province, argentina.
