Taxonomic revision of New World species of the genus Oosternum Sharp. III. A new species of O. aequinoctiale species group from Costa Rica (Hydrophilidae: Sphaeridiinae: Megasternini)

Abstract

Oosternum cicatricosum sp.n. (Hydrophilidae: Sphaeridiinae: Megasternini) is described from Costa Rica (Puntarenas Province). The species belongs to the O. aequinoctiale species group and is very similar to O. acutheca Fikáček, Hebauer & Hansen, 2009 and O. attenuatum Fikáček, Hebauer & Hansen, 2009.

Drawings and SEM photographs of diagnostic characters of the species are provided. Additional characters omitted in previous studies are explained and discussed.

Keywords

• Coleoptera
• Hydrophilidae
• Sphaeridiinae
• Oosternum aequinoctiale group
• new species
• Neotropical Region
• Costa Rica
• morphology