Omalium rivulare (Paykull, 1789)

Material. Kharkiv region: environs of Haidary, moist ravine forest, on old carpophores of Fistulina hepatica, 29. V.1992, 20 spec. ; ditto, moist ravine forest, on mature carpophores of Trametes versicolor, 29. V.1992, 2 spec. ; ditto, moist ravine forest, on old carpophores of Trametes versicolor, 30. V.1992, 58 spec. ; ditto, on carpophores of Stereum hirsutum, 31. V.1992, 1 spec.; ditto, highland oak forest, on soil on old carpophores of Coprinus micaceus, 8. VI.1992, 1 spec.; ditto, on soil in old and rotten carpophores of Agaricus silvaticus, 23. VI.1992, 1 spec.; ditto, moist ravine forest, on old and rotten carpophores of Kuehneromyces mutabilis, 23. VI.1992, 1 spec.; ditto, highland oak forest, on fallen trees, on old carpophores of Artomyces pyxidatus, 26. VI.1992, 1 spec.; environs of Chuhuiv, forest belt, on soil on carpophores of Lactarius insulsus, 30. VIII. 1992, 3 spec. (Supplement, Tab. 1).

Bionomics. Beetles inhabit natural and anthropogenic biotopes, where they live in forest cover, plant remains, under bark of trees, in rotten wood, in mosses, on flowing sap of trees and in nest chambers of small mammals.As facultative mycetobiont, they occur in old and rotten carpophores of fungi.

Distribution. Europe, Caucasus, Asia Minor, North America (Schülke & Smetana 2015).