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
2.
Pachybrachis quadrioculatus
Fall, 1915
(
Fig. 2
, Map 1A)
Pachybrachys quadrioculatus
Fall 1915: 429
.
Pachybrachis quadrioculatus
:
Fattig 1948: 10
(regional species list);
Kirk 1969: 89
(regional species list);
Riley
et al.
2003: 163
(catalogue);
Ciegler 2007: 181
(taxonomy).
Type Material.
Fall’ s male type, herein designated as
lectotype
and labeled “TYPE [printed] / 4- oculatus [hand-inked, white paper] // H. C. FALL / COLLECTION [printed, white paper] // Ga. [printed, white paper] //
Pachybrachys
/ 4- oculatus / Fall. [hand-inked, white paper with pink-lined border] // M.C.Z. / TYPE [printed] / 24975 [hand-inked, red paper] //
LECTOTYPE
24975 /
Pachybrachys
/
quadrioculatus
Fall 1915
/
R. J. Barney
2017 [printed, red paper]”, was examined and photographed (
Fig. 2
)
.
Redescription. Male.
Small, head and prothorax rufo-testaceous, elytra pale yellow, each with a small humeral and subapical spot; L =
1.79–2.12 mm
(mean =
1.89 mm
,
n
= 10); W =
0.90–1.20 mm
(mean =
1.07 mm
,
n
= 10); L/W = 1.70–1.86 (mean = 1.77,
n
= 10).
Head:
Slightly wider than thoracic apex, HW =
0.65–0.79 mm
(mean =
0.69 mm
,
n
= 10); eyes narrowly separated, IOD =
0.12–0.20 mm
(mean =
0.17 mm
,
n
= 10); IOD/HW = 0.17–0.27 (mean = 0.25,
n
= 10); face yellow with brown, W-shaped macula connecting the vertex and bases of antennae and up to base of upper lobes of eyes; antennae yellow to brown, not reaching elytral declivity.
Pronotum:
Rufo-testaceous, M-shaped macula brown, broadly diffuse to almost imperceptible; incomplete punctation to lateral margins; PL =
0.57–0.78 mm
(mean =
0.68 mm
,
n
= 10); PW =
0.88–1.04 mm
(mean =
0.91 mm
,
n
= 10); PL/PW = 0.72–0.77 (mean = 0.74,
n
= 10).
Elytra:
Yellow, striae mostly regular, baso-sutural punctures confused, punctures brown, standard maculae reduced to a small humeral and subapical spot on each elytron.
Pygidium:
Brown with 2 large, oval, yellow maculae.
Venter:
Brown, upper sides of last ventrite yellow.
Legs:
Yellow and brown.
Genitalia:
Median lobe in en-face view parallelsided, abruptly narrowing at ALM to extended tip; in lateral view, ALA 40° with setae along edges (
Fig. 2
). Nine males from two states were dissected.
Female.
As in male, except L =
2.04–2.20 mm
(mean =
2.13 mm
,
n
= 9); W =
1.13–1.24 mm
(mean =
1.20 mm
,
n
= 9); L/W = 1.72– 1.82 (mean = 1.77,
n
= 9); HW =
0.74–0.81 mm
(mean =
0.77 mm
,
n
= 9); IOD =
0.20–0.32 mm
(mean =
0.26 mm
,
n
= 9); IOD/HW = 0.27– 0.42 (mean = 0.33,
n
= 9).
Remarks.
Pachybrachis quadrioculatus
was obviously named to reflect the four spots on the otherwise pale elytra. Interestingly, Fall referred to this species in three ways:
quadrioculatus
,
quadrioculatus
, and on the
lectotype
label,
4-oculatus
. This species is relatively rare; only
53 specimens
were available for examination, yet two potential host plant species were referenced on labels.
Distribution.
Pachybrachis quadrioculatus
is only found in two states,
Georgia
and Florida, with Florida being a new state record (Map 1A).
Biological Notes.
The following potential host plants were listed on labels:
Quercus inopina
Ashe
in Florida and
Licania michauxii
Prance
(=
Geobalanus oblongifolius
(Michx.) Small
) (
Chrysobalanaceae
) in
Georgia
. Malaise and flight traps were cited on labels, as were scrub and xeric dune habitats.
Specimens Examined.
See Appendix 2.