Latvia
Invertebrates known so far only from Latvia include a grass-miner moth Elachista sulcsiella (BOLD) (PLAZI), the parisitoid wasps Rhinotorus (or Spudea) latvicus (p. 5 of ZOBODAT pdf) and Platygaster baltica (GBIF), the mites Uropoda ocellata and Oplitis latvica (both at ResearchGate), and a tardigrade Minibiotus formosus (ZooKeys ).
A fungi Cheilymenia tervetensis (figs. 1-4 at eSEIS pdf) is apparently known only from Latvia.