Obscure Sap Beetle

Description :

Conotelus obscurus, found on Rose-of-Sharon (Hibiscus syriacus) flowers. I was nearly flummoxed by these odd beetles. The elongated form and shortened elytra said "Staphylinidae", but the clubbed antennae are not typical of that family. This odd group of sap-feeding beetles, Nitidulidae, has this body form. One wonders if it might not be mimicry of a "staph". Identification: the genus has only four North American members (two in the East), and this species is distinctive and common--see the linked page on BugGuide. Length is just over 4 mm.