Borealis means northern. In its native range, this is the most northerly species of its genus.
Range
Native to Japan, introduced to New World (California, Alabama, and Peru) by shipping.(1) The species was first collected in 1993 in California and Alabama.
Habitat
"Like Paraphrosylus, species of Thambemyia live exclusively in the intertidal zone of rocky seashores or coral reefs. The predaceous larvae live among barnacles in the littoral zone and pupate in the valves of dead barnacles."(1)
Food
Larvae mainly eat larvae of Chironomidae.
Print References
Brooks, Scott E. and Jeffrey M. Cumming. 2009. First record of a Japanese marine shore dolichopodid fly, Thambemyia (= Conchopus) borealis (Takagi), from the Neotropical Region (Diptera: Dolichopodidae). Zootaxa 2112:65-67 (online via mapress)
Masunaga, Kazuhiro et al. 1999. A Remarkable Disjunct Introduction of Conchopus borealis Takagi to the New World (Diptera : Dolichopodidae). Entomological Science 2(3):399-404 (online)