A taxonomic review of the Xanthonia species occurring in Texas (Coleoptera: Chrysomelidae, Eumolpinae)
Author
Riley, Edward G.
Author
Weisman, Donald M.
Author
Quinn, Michael A.
text
Zootaxa
2019
2019-09-09
4668
1
1
29
journal article
25560
10.11646/zootaxa.4668.1.1
bb8db045-2674-4e59-ac63-d1f909d1dcfb
1175-5326
3414686
1C31A386-FA1A-4839-8BC1-90BE5BB9557D
5.
Xanthonia villosula
(F. E. Melsheimer)
(
Figs 9
, 16, 19, 36–39;
Map 6
)
Eumolpus Villosus
F. V.
Melsheimer 1806: 47
[
nomen nudum
].
Eumolpus villosulus
F. E.
Melsheimer 1847: 169
.
Myochrous villosulus
: F. E.
Melsheimer 1853: 125
.
Xanthonia villosula
: Crotch 1873: 96
.
Gemminger & Harold 1874: 3376
. Clavareau 1914: 75.
Leng, 1920: 292
.
Staines & Weisman 2001a: 178
.
Riley et al. 2003: 153
.
Eumolpus plagiatus
F. E.
Melsheimer 1847: 169
[as
Eumolpus villosulus
, var.? a].
Myochrous plagiatus
: F. E. Melsheimer 1835:125
[as valid species].
Staines & Weisman, 2001a:178
[as
nomen nudum
].
Syntype
. Not examined, sex undetermined but probably
♀
, conserved in MCZ [MCZ type no. 29396] (images at MCZ type database last viewed February, 2019). This species was originally based on an unknown number of specimens from
Pennsylvania
.
Weisman (1960)
based his interpretation of this species on Melsheimer’s original description.
Staines and Weisman (2001a)
designated a
neotype
(examined, ♂, Fig 16, conserved in
USNM
), stat- ing that they could not locate
syntype
material; however, this
neotype
designation is invalid since a
syntype
exists (ICZN Art. 75.8). The
syntype
at the MCZ had been dissected prior to this study and the abdomen is glued to the specimen’s point. There is no microvial associated with the specimen (P. Perkins, personal communication to EGR, 2017). The margins of ventrites III–IV are finely serrate.
The name
Eumolpus plagiatus
of F. E.
Melsheimer (1847)
was mentioned as a variety of
E
.
villosulus
and accompanied by a diagnosis in that work. This name was treated as a
nomen nudum
by
Staines & Weisman (2001a)
and
types
were not located. This name is available from its original publication date and is here perpetuated as a junior synonym of
X. villosula
. It applies to either the maculate form of
X. villosula
or possibly to a different maculate species occurring in the geographical area where Melsheimer acquired his specimens.
Diagnosis
. Moderate in size, length
2.8–3.5 mm
; ground color of dorsum light reddish brown, usually immaculate or rarely with faint indications of elytral maculae (
Figs 9
, 16), venter brown; punctures of elytral disc in regular rows; hairs on elytral intervals long and suberect, those emerging from punctures short and appressed; ventral tooth of profemur minute; lateral margins of ventrites III–V finely evenly denticulate (
Fig 19
); median lobe of male genitalia gently tapered distally, apex abruptly truncate with weak emargination (
Figs 36–38
).
Range
. Southern Ontario and Quebec south to
South Carolina
,
Tennessee
and
Mississippi
, west to
Wisconsin
,
Nebraska
,
Kansas
,
Oklahoma
and
Texas
(
Staines & Weisman 2001a
). The records of Dawson, Yukon, and “
Colorado
” cited in
Staines & Weisman (2001a)
seem out of the expected range for this species and are likely incorrect. The specimens supporting these records should be reexamined. The specimens cited from Travis County,
Texas
in that work were not examined during the present study. In
Texas
, this species is known from the eastern one-third of the state (
Map 6
).
Plant associations
. This common and wide-ranging eastern species has been associated with numerous woody plants, with some of those records probably being based on other
Xanthonia
species (Clark, et al. 2004). The oak associations likely represent true food plants. Some
Texas
specimens were beaten from
Quercus nigra
L. and
Q. sellata
Wangenh
..
Seasonal distribution
.
Texas
specimens were taken from April through June.
FIGURES 55–60
.
Xanthonia
species, types and type labels.
55)
X. dentata
;
56)
X. parva
;
57)
X. hirsuta
;
58)
X. angulata
;
59)
X. striata
,
60)
X. nitida
.
Remarks
. A fair number of the specimens examined from Fannin County have faint to distinct dark maculation on their elytra, but otherwise the elytral color of the examined
Texas
material is pale. The finely and uniformly denticulate ridge on the margins of ventrites III–V and the shape of the median lobe are the important diagnostic characters separating this species from all other species of similar size and coloration.
Specimens examined
. See Appendix 4. The genitalia of
15 males
from 10
Texas
localities were examined and from many additional specimens not from
Texas
.