Definition and Revision of the Atomarius Species-Group of North American Pachybrachis Chevrolat (Coleoptera: Chrysomelidae: Cryptocephalinae), Including Descriptions of Nine New Species
Author
Barney, Robert J.
text
The Coleopterists Bulletin
2018
2018-03-23
72
1
9
74
http://dx.doi.org/10.1649/0010-065x-72.1.9
journal article
10.1649/0010-065X-72.1.9
1938-4394
5381313
urn:lsid:zoobank.org:pub:69C3E6FD-3835-4B7D-BA21-76DE061F8D7D
9.
Pachybrachis matthewi
Barney
,
new species
Zoobank.org/
urn:lsid:zoobank.org:act:
833E1B49-65C4-4AE2-A0C8-9A8FF73E6A87
(
Fig. 9
, Map 2A)
Holotype
.
Male
, labeled “KY:
Trigg Co.
/ Fort Campbell 41-01 /
36.689156
o
N
, -
87.686699
o
W
/
18 June 2008
/
R. J. Barney
[printed, black on white] // [circular blue disc signifying dissection by RJB] //
Pachybrachis
/ #30 [hand-written, white paper] / det.
E. G. Riley
2009 [printed, white paper] //
HOLOTYPE
/
Pachybrachis
/
matthewi
/
R. J. Barney
2017 [printed, red paper]”. Deposited in MCZ. The specimen is point-mounted with genitalia affixed to the point. It is in excellent condition with all appendages intact. There are
seven paratypes
(566
2♀♀
) with identical collecting data.
Paratypes
.
13966
158♀♀
. See Appendix 9.
Description. Male.
Large, yellow with reduced brown-black maculae; L =
2.07–2.42 mm
(mean =
2.18 mm
,
n
= 10); W =
1.10–1.22 mm
(mean =
1.17 mm
,
n
= 10); L/W = 1.80–1.92 (mean = 1.87,
n
= 10).
Head:
Slightly wider than thoracic apex, HW =
0.73–0.83 mm
(mean =
0.77 mm
,
n
= 10); eyes moderately separated, IOD =
0.18–0.26 mm
(mean =
0.22 mm
,
n
= 10), IOD/HW = 0.25–0.33 (mean = 0.29,
n
= 10); face yellow with brown to black, W-shaped macula connecting vertex and bases of antennae and up to base of upper lobes of eyes; punctation dense in black areas, sparser in pale areas; antennae brown to black, reaching elytral declivity (
Fig. 9
).
Pronotum:
Yellow with brown to black, M-shaped macula broad, not sharply defined and usually reduced to fragments; punctation dense in dark areas, more sparsely placed in pale areas, especially along lateral margins; PL =
0.67–0.80 mm
(mean =
0.71 mm
,
n
= 10); PW =
0.94–1.12 mm
(mean = 1.00 mm,
n
= 10); PL/PW = 0.68–0.74 (mean = 0.71,
n
= 10).
Elytra:
Yellow with brown to black maculae often reduced to 3 small lateral spots and 3 adjacent mid-elytral spots; striae especially confused in basosutural region and incomplete basally, most regular laterally and apically, very little inter-strial punctation (
Fig. 9
).
Pygidium:
Finely punctate, weakly convex; brown to black with large, confluent, oval, yellow maculae occupying majority of surface.
Venter:
Black, upper sides of last ventrite yellow.
Legs:
Black with brown and yellow femoral and tibial spots; front claws not distinctly enlarged.
Genitalia:
Median lobe in enface view very wide, sides parallel to ALM,then gently curved to terminus; pre- and post-orificial lengths negligible, thus OS very large, with large, pigmented basal plates occupying half OS; median lobe in lateral view with inflated base, narrowing to a ridge-like keel at ALA, formed by 2 shallow depressions as seen from sub-en-face view; DEO deflexed at near 60° angle, without denticles or beards (
Fig.9
). Fifty-six males from seven states were dissected.
Fig. 9.
Pachybrachis matthewi
holotype. A) Dorsal habitus, B) Lateral habitus, C) Face, D) Pygidium, E) Median lobe of aedeagus, lateral view, F) Median lobe of aedeagus, en-face view.
Female.
As in male, except L =
2.28–2.67 mm
(mean =
2.51 mm
,
n
= 11); W =
1.25–1.44 mm
(mean =
1.38 mm
,
n
= 11); L/W = 1.76– 1.86 (mean = 1.82,
n
= 11); HW =
0.83–0.97 mm
(mean =
0.90 mm
,
n
= 11); IOD =
0.26–0.36 mm
(mean =
0.30 mm
,
n
= 11).
Etymology.
This species is named in recognition of Matthew Robert Barney, Heartland Master PIT Trainer, Frito-Lay North America, Inc., Louisville,
Kentucky
.
Remarks.
Pachybrachis matthewi
is very similar to
P. varians
and may eventually be determined to be a more northern variation.
Pachybrachis matthewi
is larger than
P. varians
, with reduced maculation, greater interspace punctation, and longer antennae. The median lobe of the aedeagus is significantly wider in en-face view, but the overall configuration is very similar (
Figs. 8
and
9
).
Distribution.
This species is found in the mid-
Mississippi
River Valley from
Missouri
and
Kentucky
to
Oklahoma
and
Alabama
(Map 2A).
Biological Notes.
I collected this species on
Hypericum dolabriforme
Vent.
in
Kentucky
and on
Hypericum
spp.
in
Oklahoma
and
Tennessee
. Labels also cited potential host plants as
Rhus aromatica
Aiton
in
Kentucky
and
Apocynum sibiricum
Jacq.
(=
cannabinum
L.) (
Apocynaceae
) in
Illinois
.
Specimens Examined.
See Appendix 9.