First known larva of omicrine genus Psalitrus d'Orchymont (Coleoptera, Hydrophilidae) Author Minoshima, Yusuke N. text Deutsche Entomologische Zeitschrift 2019 66 1 107 118 http://dx.doi.org/10.3897/dez.66.34300 journal article http://dx.doi.org/10.3897/dez.66.34300 1860-1324-1-107 DF52E1336C6044E7B8CBD4DF24E9E8D0 Psalitrus d'Orchymont , 1919 Diagnosis. Larva of Psalitrus can be distinguished from other known omicrine larvae ( Omicrus Sharp, 1879, Peratogonus , and unidentified larva of Noteropagus or Paromicrus ) by: (1) nasale with four distinct teeth; (2) asymmetrical median projection on nasale absent; (3) epistomal lobe absent; (4) mentum very deeply emarginate dorsally; and (5) legs four-segmented. The Psalitrus larva is also similar to other terrestrial sphaeridiine larvae; however, it can be distinguished by the addition of following combination of characters: (1) coronal line absent; (2) PA6 and PA13 absent; (3) antennomere 2 with a small basal additional pore dorsally; (4) antennal sensorium slender, long; (5) mandibles almost symmetrical, both mandibles with two teeth; (6) MN1 close to MN2; (7) MN2-4 forming a triangular group; (8) maxillae symmetrical; (9) maxilla with well-sclerotised inner appendage; (10) submentum without large lateral extension; (11) labium without hypopharyngeal lobe; (12) LA10 stout seta; (13) legs short, four-segmented; and (14) median lobe of spiracular atrium with median emargination posteriorly.