The South American rice miner (SARM), Hydrellia wirthi Korytkowski, is a new invasive insect pest of rice in the United States. The species was first described from collections in rice fields from Peru and Colombia. It was reported for the first time in the United States from rice fields in Louisiana in 2004. The species was then reported in different rice areas of Louisiana and Texas. The SARM is a shore fly (Diptera: Ephydridae). The only shore-fly species previously known to infest commercial rice in the US was the smaller rice leafminer, Hydrellia griseola (Fallen). A field survey for the SARM was conducted in the most important rice producing areas of Louisiana and Texas. The objective of the survey was to determine the distribution of this new invasive species and to assess the severity of infestations in rice fields. Efforts were focused to inspect rice fields from one to six weeks of emergence. Commercial rice fields were scouted using a standard 15-inch sweep net. Ten sweep passes at five different locations were performed in each field. Fly adults (dipterans) were collected from nets using a mouth aspirator. Suspicious dipterans were preserved in 70% ethyl alcohol and forwarded to the USDA-ARS-Systematic Entomology Laboratory (SEL) identifier for official confirmation to species level. In addition, suspected damaged plants were taken to a laboratory and fly larvae reared until adult emergence. Fly adults and associated parasitoids emerged in the laboratory were shipped in vials containing 70% ethyl alcohol. A total of 15 different Louisiana parishes were surveyed which included 1223 hectares (3023 acres) of rice. The following parishes were surveyed in 2005: Vermilion, 260 hectares (642 acres); Acadia, 191 hectares (471 acres); Lafayette, 12 hectares (30 acres); St. Landry, 85 hectares (210 acres); Jefferson Davis, 168 hectares (414 acres), Allen, 103 hectares (254 acres); Calcasieu, 45 hectares (110 acres); St. Martin, 81 hectares (200 acres); Cameron, 81 hectares (200 acres); Evangeline, 12 hectares (30 acres); Avoyelles, 36 hectares (90 acres); Concordia, 133 hectares (328 acres); Tensas, 3 hectares (7 acres); Franklin, 2 hectares (5 acres); East Carroll, 13 hectares (32 acres). Forty five vials containing suspicious fly samples (including 5 vials with emerged parasitoids) were sent to the SEL identifier for identification to species level. The field survey revealed that the SARM is widely distributed in all the important rice producing areas of Louisiana. Higher infestations, i.e. those causing significant yield losses, were observed in coastal parishes including Cameron, Jefferson Davis, Acadia and Vermilion parishes. The insect was found at very low levels in other rice areas of southwest, central and northeastern Louisiana including Calcasieu, Allen, St. Martin, Concordia and Tensas parishes. The distribution of the species in Texas counties includes Calhoun, Colorado, Jackson, Jefferson, Matagorda, and Wharton counties.