Stenocorus Geoffroy, 1762

Stenocorus is presently considered to consist of 30 species in 2 subgenera worldwide, with 12 species occurring in North America. Our four Pacific Northwest species can be distinguished as follows: 

S. flavolineatus (LeConte, 1854) - above. The largest species, 17-27 mm. The easiest character to separate the smaller specimens is the basal margin of the pronotum, which is strongly sinuate (curved) and broadly lobed at the middle. The elytra usually have broad, black and yellow stripes, but can be all black. 

S. nubifer (LeConte, 1859) - above.The apices of the elytra are obliquely truncate. This is the most variable species in our region, the entire population having at one point been considered to be as many as 12 distinct species (see species page). 

​S. obtusus (LeConte, 1873) - above.  The apices of the elytra are rounded and only sparsely pubescent.

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S. vestitus (Haldeman, 1847) - above. The apices of the elytra are rounded, but densely clothed with appressed, often golden pubescense. 

Taxonomic History of Stenocorus
“Antennae a vasi ad apecim decrescentes, ante oculos positae. Elytra apice angustiora,”
   - (Geoffroy, 1972) 

Geoffroy's original (1762) concept of Stenocorus was fairly different from our modern use of the term. His twelve species, which had antennae 'smaller from the base towards the tip, and positioned before the eyes'  included not only the familiar Rhagium inquisitor (Linnaeus,1758) but also Linnaeus' Leptura aquatica, which today we recognize as Donacia aquatica in the family Chrysomelidae. Geoffroy's 3rd species, described as new (p. 223), appears to be the same as Linnaeus' Leptura meridiana ​(see reference in Latreille, 1758 p. 310).  Fabricius (1775), who was the first to characterize Stenocorus in the standard Latin binomial format, included meridiana L. as his first species, but made no reference to Geoffroy. 

Geoffroy used polynomial, rather than binomial taxonomic terms, and for this reason was placed on the Official Index of Rejected and Invalid Works in Zoological Nomenclature.  The type for Stenocorus was later designated by Plavilstchikov (1936) as Leptura meridiana Linneaus, 1758. The International Commission on Zoological Nomenclature (ICZN, 1994: Opinion 1754) later upheld this type designation, when it decided that 24 of Geoffroy's genus names, and only his genus names, could be considered available to taxonomy. 

For over a century the North American species now attributed to Stenocorus were considered by American authors to be part of the genus Toxotus Dejean, after the term’s introduction by Haldeman (1847). Toxotus Dejean was synonymized under Stenocorus Fabricius, 1775  by Hopping (1928), and this classification was adopted by Casey (1913) and Linsley and Chemsak (1972).  

Etymology
Stenos (narrowed) + coros (particularly), after the particularly narrowed elytra in some species.