Postelichus
Nelson, 1989
long-toed water beetles
Species Guides
1Postelichus is a of long-toed water beetles in the Dryopidae, established by Nelson in 1989. The genus contains seven described distributed in North America, with the earliest described species dating to 1852. Members of this genus are associated with aquatic or semi-aquatic , consistent with the family Dryopidae's ecological preferences.
Pronunciation
How to pronounce Postelichus: //pɒˈstɛlɪkəs//
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Identification
Postelichus can be distinguished from other Dryopidae by their elongated with particularly long terminal segments, the characteristic that gives the group its of "long-toed" water beetles. The genus was separated from Elmis based on differences in tarsal structure and male genitalia. Species-level identification requires examination of aedeagal and subtle differences in elytral punctation and coloration patterns.
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Distribution
The Postelichus is restricted to North America. Described are known from the western United States and Mexico, including California and Baja California. The type species, Postelichus productus, was described from California in 1852.
Similar Taxa
- ElmisHistorically, Postelichus were classified within Elmis; the two share similar overall body form and aquatic habits, but Postelichus is distinguished by its elongated tarsal segments and distinct male genitalic structure.
- Other Dryopidae generaWithin the Dryopidae, Postelichus is recognizable by its characteristic long-toed , which are more elongated than those of related such as Dryops or Helichus.
More Details
Taxonomic History
The was erected by Nelson in 1989 to accommodate previously placed in Elmis, based on phylogenetic analysis of morphological characters. The type species is Postelichus productus (LeConte, 1852), originally described as Elmis productus.
Species Diversity
Seven are currently recognized, with the most recent description being Postelichus bajaensis Barr and Shepard, 2022 from Baja California, Mexico. Five of the seven species were originally described by Hinton between 1935 and 1937.