Synonyms and other taxonomic changes
First described in 1832 by James Francis Stephens
. The correct spelling according to the Greek should be Rhizobius
, but the rules don't allow a correction in this case. As a result, both spellings are widespread.
Explanation of Names
from Greek rhiza (ριζα)- "root" + bios (βιος)- "life, way of life". The species best known at the time lives at the roots of plants.
Two introduced species in North America:
Dark reddish-brown or black
Densely pubescent (hairy), with a layer of short fine hairs interspersed with some longer hairs; densely "fuzzy" appearance.
Eyes not pubescent
Rhyzobius forestieri: Western California.
Rhyzobius lophanthae: Transcontinental in the southern U.S.
Dusky Lady Beetles of Tribe Scymnini look extremely similar, with dark brown or black coloration and pubescence. However, all members of Tribe Scymnini have pubescent eyes and none are metallic. They also have hairs of a single length, not two layers of longer and shorter hairs like Rhyzobius.
Illustrations of British Entomology, p.396
Stephens' original description of the genus.