The South American moth Porphyrosela minuta Clarke (Gracillariidae) is documented for the first time in the United States, where it is already widespread. The larvae are leafminers of white clover (Trifolium repens L., Fabaceae). Adults and larval habits are compared with those of the native Nearctic P. desmodiella (Clemens), which mines leaves of several other legumes.We summarize and add to the known distribution and parasitoid records for both species.