Sternopriscus clavatus
Ordo: Coleoptera
Familia: Dytiscidae
Genus: Sternopriscus
Name
Sternopriscus clavatus Sharp, 1882
Type locality
Sydney, New South Wales, Australia.
Type material
Lectotype: male "Hydroporus clavatus Wehncke, male Type mihi Sydney D.S.", "Lectotype", "Type", "Australia", "New S. Wales Australia", "Sharp Coll. 1905-313", "Type 161 Hydroporus clavatus Wehncke", "Hydroporus clavatus Sydney", "Sternopriscus Hansardii CLK = clavatus Shp J. Balfour-Browne det." (BMNH). - Paralectotypes: 1 female "Hydroporus clavatus Wehncke, female Type mihi Sydney D.S.", "Paralectotype", "Type", "New S. Wales Australia", "Sharp Coll. 1905-313", "Sternopriscus Hansardii Clk = clavatus Shp J. Balfour-Browne det.", "Sternopriscus clavatus Sharp 1974 Det. C. Watts 1974" (BMNH); 1 female "Hydroporus clavatus Wehncke", "Paralectotype", "Cotype", "Australia", "Australia", "Sharp Coll. 1905-313", "Sternopriscus clavatus Sharp Det. C. Watts 1974" (BMNH).
DNA Sequences
European Nucleotide Archive (ENA)
Description
Measurements: Males: TL = 4.04 - 4.28 mm, TL-H = 3.72 - 3.92 mm; width = 2.00 - 2.08 mm. Females: TL = 3.32 - 3.76 mm, TL-H = 3.00 - 3.48 mm; width = 1.72 - 2.00 mm.
Colour: Head testaceous, variably sized area inwards from eyes and along rear edge dark brown to black; pronotum testaceous, front margin broadly dark brown to black, rear margin with broad bilobed dark area in centre and narrow area of dark brown to black along rear to variable extent; elytron dark brown with three large lateral testaceous patches, the foremost not reaching humeral angle, three smaller patches near suture and some smaller linear areas near base, apex testaceous. Ventral surface light to dark brown, appendages somewhat lighter, antennal segments 3 - 7 and tips of palpi darker.
Sculpture: Elytral edge weakly serrate and weakly expanded towards apex, expansion ending abruptly close to apex. Pronotal plicae weak, reaching a bit beyond half way along pronotum. Prothoracic process robust, narrow between coxae then slightly widening before narrowing to broad tip, strongly rugose- punctate, reaching mesosternum, weakly ridged in apical portion. Metasternum strongly keeled in midline, strongly raised in middle in front. Metacoxal lines raised, well separated, moderately diverging in basal half and extreme apex.
Male: Larger. Antennal segment 6 enlarged, segment 7 greatly enlarged, segment 8 about half length of segment 7 and same width, segments 9 and 10 weakly enlarged, apical segment enlarged as wide as segment 10 longer than segments 9 and 10 combined, segments 7 and 8 concave beneath. Pro- and mesotrochanters with thin ridge near apex. Protarsus moderately expanded; protibia bent near apex, thin. Mesotarsi with basal three segments moderately, asymmetrically expanded; mesotibia curved, broadened towards apex, dense tuft of setae in inner apical angle, mesofemur with small protrubance at base on inside. Median lobe of aedeagus broad, tip complex, lacking finger-like ventral projection; parameres broad, strongly bent in middle.
Female: Smaller; appendages simple; tarsi less expanded than in male, symmetrical.
Affinities
A member of the S. hansardi group, the dark tips to the maxillary palpi and extensive testaceous colour on the ventral surface separate S. clavatus from all group members other than S. goldbergi and S. weiri. Sternopriscus clavatus is larger (3.3 - 4.3 mm) than S. goldbergi (2.6 - 3.0 mm), which is only known from the Northern Territory whereas S. clavatus is restricted to eastern Australia. It differs from S. weiri by the stronger (although still weak) pronotal plicae, which are scarcely traceable in S. weiri. Otherwise characters of the aedeagus and antennae separate the three species.
Habitat
All kinds of permanent standing and slow flowing water (ditches, intermittent creeks, protected embayments of slow flowing rivers, ponds and dams).
Distribution
Common in eastern and southeastern Australia: S Gulfs, Murray-Darling basin, SE coastal, NE coastal, Tasmania, South Australia, Australian Capital Territory, Victoria, New South Wales and Queensland (Watts 1978; Lawrence et al. 1987). The single record from the highlands of Irian Jaya (Indonesia), Paniai Lakes, 1900 m, near Enarotali (Balke 1995) needs to be confirmed.
Images
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References
- Hendrich, L.; Watts, C.H.S. 2004: Taxonomic revision of the Australian genus Sternopriscus Sharp, 1882 (Coleoptera: Dytiscidae, Hydroporinae). Koleopterologische Rundschau, 74: 75–142.
