Larval morphology and chaetotaxy of three Caribbean Berosus Leach, 1817 with revised adult diagnosis of Berosus undatus (Fabricius, 1792) (Coleoptera: Hydrophilidae)

The morphology and head chaetotaxy of third instar larva of the endemic Cuban B. chevrolati Zaitzev, 1908 are described. We provided the diagnosis of third instar larvae of B. exiguus (Say, 1825) and B. cf. undatus (Fabricius, 1792). This study is based on specimens collected in Cuba and identified by associations with adults. Larvae of B. exiguus and B. cf. undatus agree well with previously described larvae of Berosus. In contrast, B. chevrolati represents an unusual morphotype, characterised by narrow and strongly projecting nasale and well-developed right epistomal lobe. We also revise the adult diagnosis of B. undatus, which was incorrectly provided by Deler-Hernandez, Fikacek, and Cala-Riquelme (2013), and provide additional characters to distinguish this species from B. interstitialis Knisch, 1924 and B. infuscatus LeConte, 1855.