Nomenclatural changes in North American Phymatodes Mulsant (Coleoptera: Cerambycidae)
Author
Swift, Ian P.
Author
Ray, Ann M.
text
Zootaxa
2010
2448
35
52
journal article
10.5281/zenodo.294195
c29f5797-e795-4f0f-b4d1-cb03eed3c385
1175-5326
294195
Phymatodes obliquus
Casey
,
NEW STATUS
(Figs 26, 27)
Phymatodes obliquus
Casey, 1891
:26
.
Type
locality: California,
USA
. USNM
Phymatodes harfordi
Casey, 1912
:279
.
Type
locality: Santa Clara County, California,
USA
. USNM
Phymatodes decussatus
var.
obliquus
,
Hardy and Preece, 1926
:28
Phymatodes decussatus
var.
latifasciatus
Hardy and Preece, 1927
:191
.
Type
locality: Mt. Tolmie, Victoria Island, British olumbia,
Canada
. CNC
Phymatodes decussatus
var.
posticus
Van Dyke, 1920
:36
;
Linsley, 1964
:51
.
Type
locality: Camp Nelson, Tulare County,California,
USA
. CASC
NEW SYNONYMY
Phymatodes decussatus australis
Chemsak, 1963:40
.
Type
locality: Ensanada, Baja California,
Mexico
. CASC
NEW SYNONYMY
Phymatodes obliquus
is the oldest name to replace the taxon in Linsley’s (1964) concept of
P. decussatus
(see the discussion of
P. decussatus
as well).
Phymatodes obliquus
can be distinguished from similar species, such as
P. decussatus
(as defined herein), by its non-setose white fasciae, which are arcuate, rather than angulate; the elytral pubescence, which is long, erect, golden and white in
P. decussatus
, and short, subappressed, and dark in
P. obliquus
; and the upper eye lobe, which is contiguous with the lower lobe by at least four rows of omatidia, while in
P. decussatus
most specimens have only a sclerotized line, lacking ommatidia.
This west coast species is similar to
P. v a r i u s
(Fabricius) from the eastern
US
, and few salient characters have been found to separate the two species. The most consistent differences are the extent of the white fasciae on the elytra, wherein
P. v a r i u s
possesses more expansive markings while in
P. obliquus
they are somewhat reduced. The basal pair is also more transverse in the former species, and more arcuate in the latter. Additionally,
P. v a r i u s
generally has more dense, dark setae at the elytral base, whereas in
P
.
obliquus
the setae are less dense and somewhat lighter. Both of these characters are difficult to interpret when examining a single specimen or even small series. Nevertheless, based on these minor differences, as well as the fact that the two populations appear to be allopatric, the two species are herein retained. However, future analyses may prove these taxa indistinct.
The subspecies previously assigned to
P. obliquus
(
P. decussatus sensu
Chemsak
), are highly variable as has been noted by several authors (
Hovore and Giesbert 1976
, Swift 2008). In southern California, specimens exhibiting characters of both subspecies have been reared from the same logs, and long series from any region vary widely in form and coloration. Thus, it seems best to treat this species as a single highly variable taxon.
This species as well as
P. v a r i u s
,
P
.
dimidiatus
, and
P
.
vulneratus
have pronounced sexual dimorphism. The metathoracic legs are longer and more robust in males; and the pronotum is broadly rounded at the sides in males, while in the females it is feebly angulate. These four species also share similar gland pore arrays on the anterior margin and pleura of the pronotum.
Specimens examined:
326, including the
types
of
P. obliquus
,
P. d. posticus
, and
P. d. australis