A Revision of the Onthophagus pexatus Species-group, with Description of a New Brachypterous Species (Coleoptera: Scarabaeidae: Scarabaeinae)
Author
Reid, Chris A. M.
Author
Runagall-Mcnaull, Aidan
text
Records of the Australian Museum
2022
Rec. Aust. Mus.
2022-11-30
74
5
131
150
http://dx.doi.org/10.3853/j.2201-4349.74.2022.1821
journal article
10.3853/j.2201-4349.74.2022.1821
2201-4349
13228969
364EB32F-A79D-41E4-BFCF-F28142C2D51B
Onthophagus squalidus
Lea, 1923
Figs 9–10
,
23–24
,
29
,
34
,
41
,
45
Onthophagus squalidus
Lea, 1923: 390
; Boucomont & Gillet, 1927: 216;
Matthews, 1972: 211
; Cassis & Weir, 1992: 151; Monteith & Kenyon, 2011: 57; Reid
et al
., 2022.
Material examined
(
9♂
,
6♀
).
New South Wales
:
2♂
/
Boonoo Boonoo NP
,
28.7998°S
152.1859°E
983 m
Site
114
Colongan Rd
, burnt tall dry scler., macropod dung baited
pitfall
3–4.iv.2021
Reid
& Runagall-McNaull (
AMS
)
;
1♂
*/
Boorook SF
, 09AM
1 km
E of main rd
28°49'S
152°11'E
900 m
(NPWS
Survey
)
4.ii–9.iv.1993
M Gray G Cassis
(
AMS
)
;
2♀
/
Boyne SF
, jn
Windywoppa
&
Lookout Rds
,
35°36'28"S
150°12'28"E
, CBCR003-048
17.iii.1999
J
Tarnawski
& S
Lessau
(
AMS
)
;
1♀
/
Carrai SF
38AR
Fife
Fire Trail
,
1.6 km
NE Fifies Knob Rd
30°55'S
152°23'E
670 m
(NPWS
Survey
)
4.ii–9.iv.1993
M Gray G Cassis
(
AMS
)
;
1♂
/
Cathedral Rock NP
30.4416°S
152.2790°E
1347 m
site 61 c2k from park entrance, burnt dry scler/open heath, macropod dung baited
pitfall
22–23.ii.2021
Reid
& Runagall-McNaull (
AMS
)
;
1♂
,
1♀
/
Donaldson SF
28.3418°S
152.6693°E
524 m
Site
113
Summerland Way
nr
Rabbit Fence
trail, burnt wet scler, macropod dung baited
pitfall
2–3.iv.2021
Reid
& Runagall-McNaull (
AMS
)
;
1♀
/
East Kunderang Trail
39AR
2.1 km
E of West Kunderang Trail
30°49'S
152°03'E
845 m
(NPWS
Survey
)
4.ii–9.iv.1993
M Gray G Cassis
(
AMS
)
;
1♂
/
Richmond Range SF
47A 04
AR Goanna Ck Rd
,
28°36'S
152°41'E
545 m
(NPWS
Survey
)
4.ii–9.iv.1993
M
Gray
G
Cassis
(
AMS
)
;
1♀
/
Sydney
[sic],
Francis Greenway HS
, leaflitter, cowpasture
10.v.2001
,
Vacy
(
AMS
)
;
1♂
*/
Upper Hunter River
, mature riparian strip,
Denman Vineyard
at
Denman
32°20'36"S
150°44'18"E
Denman S
1/2P
pit trap
23.xi–9.xii.2004
J Gollan
(
AMS
)
;
1♂
, ditto except
Denman S
1/1
YP yellow pan trap
(
AMS
)
;
Victoria
:
1♂
*/
4
miles
W Melton
3.ii.1974
PJ
Gullan
(
AMS
)
.
Additional records
(not included in
Matthews, 1972
).
Australian National Territory
: 1/ 6k NE Piccadilly Circus (
ANIC
);
New South Wales
: 1/ Byrrill Ck (
QMB
); 1/ Calosoma HS (
ANIC
); 3/ W end Coolah Tops (
QMB
); 1/ 2.5K W Minyon Falls (
QMB
); 1/ 4k NE Mt Wog Wog (
ANIC
); 1/ Styx R SF (
ANIC
); 1/ Unumgar SF (
ANIC
);
Queensland
: 1/ Belmont Hills (
QMB
); 8/ Buhot Creek (
QMB
); 1/ Bulimba Creek (
QMB
); 1/ Burleigh Headland NP (
QMB
); 2/ 14k & 21k SSW Canungra (
QMB
); 1/ Levers Plateau (
QMB
); 1/ Mt Cotton (
QMB
); 1/ Mt Gannon (
QMB
); 9/ Mt Huntley (
QMB
); 1/ Mt
Superbus (QDAF)
; 8/ Passchendaele SF (
QMB
); 2/ Sankeys Scrub (
QMB
); 3/ 6k WNW Stanthorpe (
QMB
); 1/ Tallebudgera Valley (
QMB
); 7/ Vickerman Reserve (
QMB
).
Redescription
. Mature specimens dull blackish-grey, head and pronotum shiner than duller and densely microsculptured elytra and pygidium; teneral (or recently emerged specimens) with reddish-brown elytral apices, sides of apical ventrites and legs; antennae reddish-brown, with orange to dark brown clubs. Length, male
4.5–7 mm
; female
4.5–6.5 mm
.
Male
. Head (
Fig. 23
). Surface smooth, shallowly microreticulate, dull to slightly shiny in basal half and shinier in apical half, with close punctures, separated by about 1× diameters at base becoming smaller and sparser towards apex, minute stubble on base of frons and short semi-erect setae on apex of clypeus. Clypeal apical margin uptilted, arcuately excavate, each side of excavation triangularly produced, side margins slightly rounded; clypeal suture entirely effaced at frontal portion, genal suture present (completely effaced on
one specimen
) but not raised; frons flat, without elevations, slightly medially depressed; eyes narrow, 5–7 facet rows in width, separated by 15–20 eye widths, canthus narrowly complete; mentum shallowly excavate at apex.
Thorax (
Figs 9–10
,
29
,
34
). Pronotum. Broad in large males (as wide as elytra), narrower and flatter in small males. Moderately convex, slightly tumid at middle of anterior slope in larger specimens; surface smooth, midline not obviously elevated or depressed, entirely strongly and closely punctured, punctures not ocellate, slightly elongate at middle, becoming rounder and larger towards sides, intervals shiny and not microreticulate, less than half diameter of punctures, and covered in dense short curved and thickened setae (lengths less than diameter of punctures); anterior angles 80–90°; anterior margined, sides margined and crenulate with curved short setae between crenulations, base with or without thin raised edge at middle; pronotal hypomeron dull and densely microsculptured, strongly punctured on outer half, punctures separated by 1–2 diameters, with elevated rims, increasing in diameter towards sides, outermost punctures with long semi-erect setae. Elytra. Semi-ovate in dorsal view, with prominent humeri and preapical swelling, longer than pronotum along midline. Surface including striae densely microreticulate and duller than pronotum, except numerous shiny tubercles on intervals and shiny apical half of sutural margins; all intervals flat except for distinct shiny tubercles, apex of 5th interval with irregular shiny area formed by coalesced tubercles, similar but much smaller patches may be present at apices of 3rd and 4th intervals; tubercles in 2–3 irregular rows in intervals 2–7, denser on outermost interval; each tubercle with minute short curved scale-like seta, not in distinct rows, outermost interval more densely setose; strial punctures weak, slightly broader and deeper than striae; epipleura with single row of curved setae. Metaventrite medially shiny, anteriorly and laterally (lateral to mesocoxae) dull and microreticulate, with scattered semi-recumbent setae on anterior half, anterior smoothly convex, midline grooved; wing fully developed, folded twice in repose. Legs. Protibiae elongated and narrowed, inner apical angle with compact dense tuft of yellow setae about twice length of apical spur; distal face of apical tooth with loose sparse tuft of yellow setae about as long as apical spur, 4th (smallest) lateral tooth at about midpoint; metafemoral ventral surface smooth and mostly shiny, distinctly microreticulate on apical third, almost evenly punctured with moderately large punctures separated by 1–3 diameters.
Figures 49, 50
.
Onthophagus pexatus
Harold
, apices of parameres. (
49
) Dairy Park, NSW; (
50
), Woolomin, NSW.
Abdomen (
Fig. 41
). Ventrites dull, densely microreticulate, obscuring puncturation, each with single transverse row of short semi-recumbent pale setae, set on shiny tubercles on ventrites 5–6; pygidium flat or almost so, densely and evenly microreticulate except shallowly microreticulate and shinier raised margins; punctures distinct or obscured by microsculpture, sparse, separated by 1–3 diameters; setae short and thick, length 5–8× width.
Aedeagus (
Fig. 45
). In lateral view, parameres “crested”, with an angular apico-dorsal elevation and prominent but short apico-ventral “beak”.
Female
. Head (
Fig. 24
). Sides more rounded, surface rougher than male, mostly shiny, smooth at base becoming transversely rugose on clypeus, with dense large punctures throughout; median depression of vertex not deeper than male; clypeal suture slightly elevated in frontal portion, effaced before reaching genal sutures, straight, genal sutures often slightly raised; pronotum slightly narrower than elytra; protibiae short and straight, with broad lateral teeth.
Minor male
(
one specimen
).As major male but genal sutures slightly elevated and protibiae short, without setal tufts.
Notes
.
Matthews’ redescription was based on
172 males
and females, including 141 from a single locality (Canberra), and the female
holotype
from south
Queensland
.
He
recorded it along the coast and
Dividing Range
from
Victoria
to south
Queensland
.
The
material examined here fits within this range and conforms to
Matthews’
description, except that he noted a slightly different size range (
5–8 mm
long), the eyes are slightly more variable in size and the striae are distinctly but feebly punctured
.
Onthophagus squalidus
appears to be tolerant of a wider range of habitats (Reid
et al.,
2022) than indicated by Matthews, who regarded it as a woodland species. The sites recorded here vary from closed forest to open grassland. The species appears to be rare where it occurs in
New South Wales
, most records being singletons.