A revision of the water beetle genus Gymnochthebius Orchymont (Coleoptera: Hydraenidae) for Australia and Papua New Guinea
Perkins, Philip D.
Zootaxa
2005
2005-07-29
1024
1
1
161
9PSPM
Perkins, 2005
Perkins
2005
[264,599,444,470]
Insecta
Hydraenidae
Gymnochthebius
Animalia
Coleoptera
76
Arthropoda
species
squamifer
sp. nov.
Type Material. Holotype(male): Australia: Queensland:N.Q., 15 kmNE Mareeba, MDPI intercept trapsite No. 25, flight intercept trap, 16° 56' S, 145° 32' E, 20 December 1984– 7 January 1985, Storey& Titmarsh. Depositedin the QMBA. Paratypes(10): Australia: Northern Territory: 30 kmN of Wauchope, 20° 22' S, 134° 14' E, 13 October 1972, M. S. Upton(1 ANIC); Butterfly Gorge Nature Pk Douglas River, at light, 13° 45' S, 131° 34' E, 19 July 1994, T. Weir& A. Roach(1 ANIC); Queensland: 5 kmS Batavia Downs, flight intercept trap, 12° 41', 142° 41' E, 23 August–16 September 1992, P. Zborowski& L. Miller(2 ANIC); Hann River, 15° 11' S, 143° 52' E, 16 August 1992, P. Zborowski& J. Cardale(1 ANIC); Leichart Creek, 8k N Bluewater, 19° 10' S, 146° 32' E, 18 December 2002, A. J. & C. H. S. Watts(2 SAMA); Western Australia: 14 kmSbyE Kalumburu Mission, CALM Site4/3 [Western Australian Department of Conservation and Land Management], at light, open forest, 14° 25' S, 126° 40' E, 3–6 June 1988, T. A. Weir(2 ANIC); Synnot Ck., CALM Site25/1 [Western Australian Department of Conservation and Land Management], at light, open forest, 16° 31' S, 125° 16' E, 17–20 June 1988, T. A. Weir(1 ANIC). Representative specimens to be deposited in MCZ and NPC.
Differential Diagnosis.A very distinctive species, recognized by the small size, the squamiform dorsal setae, and the wide fringe of arcuate setae on the elytral lateral margins (Fig. 66). Similar to G. nanosetus(Fig. 64) in having the abdominal hydrofuge pubescence reduced to the first two ventrites, but differing in smaller size, more distinctly widened (squamiform) dorsal setae, wider fringe of setae on the elytral margins, larger elytral punctures, confluent anteriorposterior pronotal foveae, and the reduced abdominal hydrofuge pubescence, covering ventrite 1 and present basolaterally on ventrite 2. The male genitalia of the two species are quite dissimilar (Figs. 65, 67).
Description.Size (length/width, mm) holotype: body (length to elytral apices) 1.26/ 0.56; head 0.30/0.37; pronotum 0.30/0.48; elytra 0.82/0.56. Form moderately ovate, moderately convex. Dorsum dark brown, weakly shining beneath distinctive whitish or yellowish setae. Head with dorsum clothed in distinctive decumbent setae, setal sockets minutely raised; frons very sparsely punctate; interocular foveae deep; interocular tuberculi distinct; basomedial fovea narrowly confluent with interocular foveae. Frontoclypeal suture deeply impressed, bisinuate. Clypeus midlength about 0.5 apical width, nonpunctate (but setal sockets minutely raised). Labroclypeal suture straight in dorsal view, evenly arcuate in anterior view. Labrum at angle to clypeus, only very small apicomedian tooth visible in habitus view; width twice length. Maxillary palpomere 3 about twice length of 4. Pronotum distinctively setose; lateral hyaline border well developed, origin at base of lateral depression, lateral margin angulate, then continuous with very narrow posterior hyaline border; anterior margin of pronotum arcuate between lateral depressions; each lateral depression with posterior angle acute, lateral margin straight, densely clothed in long setae which form a fringe equal to 0.5 width of lateral depression; lateral fossulae deep; pronotal disc moderately convex, with short flattened narrow setae that taper from base to apex; median groove narrow, deeper in front and behind midlength, constricted in midlength, not attaining anterior and posterior margins, tapering at ends; anterior foveae well developed, transverse; posterior foveae oblique, shallow, oval, nearly attaining anterior foveae; posterolateral angles lacking impressions. Elytra clothed in distinctive decumbent flattened setae that taper from base to apex; setae serial, forming six rows between suture and humeral angle; punctures on disc large, transverse, obliterating intervals; elytra convex on disc; summit of posterior declivity at about midlength; elytral explanate margin very narrow, with fringe of long arcuate setae, those in anterior 0.5 of elytron twice as long as pronotal fringe. Metasternal glabrous area length less than width (as 10:12), subrhomboidal, shining, convex. Abdominal ventrites 1 and basolaterally 2 with hydrofuge pubescence. Aedeagus (Fig. 67): Length of mainpiece 0.20 mm, length to tip of parameres 0.21 mm; lobes relatively short, weakly subapically barbed; apical paramere seta longer than other setae. Females unknown.
Etymology.Named in reference to the widened and flattened dorsal setae.
Distribution.A wide northern distribution pattern, found north of about 20° S. latitude, with widely separated locality records in Western Australia, Northern Territory, and Queensland(Fig. 74).
1984-12-20
1985-01-07
1984-12-20
Storey & Titmarsh. Deposited
Australia
-16.933332
Mareeba
1280
145.53334
76
1
Queensland
holotype
1972-10-13
ANIC
M. S. Upton
Australia
-20.366667
30 km N of Wauchope
1268
134.23334
76
1
Northern Territory
paratype
1994-07-19
ANIC
T. Weir & A. Roach
Australia
-13.75
Butterfly Gorge Nature Pk Douglas River
1289
131.56667
76
1
Northern Territory
paratype
1992-08-23
1992-09-16
1992-08-23
ANIC
P. Zborowski & L. Miller
Australia
5 km S Batavia Downs
142.68333
76
1
Queensland
paratype
1992-08-16
ANIC
P. Zborowski & J. Cardale
Australia
-15.183333
Hann River
1286
143.86667
76
1
Queensland
paratype
2002-12-18
SAMA
A. J. & C. H. S. Watts
Australia
-19.166666
Bluewater
1273
146.53334
Leichart Creek
76
1
Queensland
paratype
1988-06-03
1988-06-06
1988-06-03
ANIC
T. A. Weir
Australia
-14.416667
Site
1288
126.666664
Kalumburu Mission
76
1
Western Australia
paratype
1988-06-17
1988-06-20
1988-06-17
ANIC
T. A. Weir
Australia
-16.516666
Site
1282
125.26667
Synnot Ck.
76
1
Western Australia
paratype