Psammoecus t-notatus Blackburn, 1903

Karner, Michael, 2020, Taxonomic Studies on Australian Psammoecus Latreille (Coleoptera, Silvanidae, Brontinae), European Journal of Taxonomy 723, pp. 135-158 : 144-146

Psammoecus t-notatus Blackburn, 1903

Fig. 4

Psammoecus t-notatus Blackburn, 1903: 154.

Psammoecus amoenus Grouvelle, 1912: 92 . Syn. nov.

Psammoecus t-notatus – Hetschko 1930: 84.

Diagnosis

The following combination of character states distinguishes this species: body oval ( Fig. 4A ), length 2.35–2.83 mm; eyes of moderate size ( Fig. 4B ), slightly unevenly rounded with somewhat stronger curvature posteriorly; temples distinct, evenly rounded; frontal grooves short, slightly curved, reaching anterior third of eyes; antennae slender ( Fig. 4D ), antennomeres 9–10 darkened; antennomere 11 testaceous; punctation on vertex moderate ( Fig. 4B ), punctures round, slightly smaller than eye facet diameter; microsculpture on vertex absent, pubescence moderate; pronotum ( Fig. 4C ) often brown with testaceous discal area of variable size, sometimes entire pronotum testaceous; widest at anterior third, lateral pronotal margins with four distinct teeth; teeth I and II small, III and IV larger; anterior and posterior denticles present, distinct; pronotal punctation dense, punctures slightly widened anteromedially, microsculpture absent, pubescence moderate, setae directed antero-medially; elytra widest at middle ( Fig. 4A ), with transverse piceous maculae closely behind middle, posterior part of suture, elytral apex and, in most specimens, humeral area darkened, interstices slightly wider than striae, pubescence moderate, microsculpture absent; male genitalia ( Fig. 4 E–F) comparatively weakly sclerotised, median lobe slender, evenly narrowed towards apex, tip of apex blunt, tegmen with wide, very weakly sclerotised basis, paramere long, slender, club-shaped, inner margin of widened basis with numerous setae, along inner margins with few short, thin setae, apex with long seta.

Material examined

Types

AUSTRALIA • ♀, holotype of Psammoecus t-notatus Blackburn, 1903; “Type | H.T.” [round label with red border]; “Australia. | Blackburn Coll. | B.M.1910-236.”; “ Psammoecus | T-notatus., Blackb.”; NHMUK.

VIETNAM • ♂, holotype of Psammoecus amoenus Grouvelle, 1912 ; Annam, Phúc Son; “Annam | PhucSon | Nov. Dez. | H. Fruhstorfer”; “ Psammoecus | amoenus | G. Grouv” [Grouvelle’s hand]; “N.L.M. 34. | p. 92.”; “Museum Leiden | Psammoecus | amoenus | Det: Grouv.”; “Type” [red label]; RMNH.

Other material

AUSTRALIA • 2 specs; Queensland, Cairns ; 16°55′ S, 145°46′ E; ANIC • 3 specs; Queensland, Cairns, Bellenden Ker Range, 1 km south of Cable Tower; 1054 m a.s.l.; 17 Oct.–5 Nov. 1981; QLD Museum leg.; rainforest, malaise trap; ANIC • 1 spec.; Queensland, Cassowary Coast Region, Cardstone ; 14 Nov. 1966; Brooks leg.; ANIC • 1 spm; same locality; 15 Nov. 1966; Brooks leg.; ANIC • 1 spm; same data as for preceding; MKF • 1 spec.; same locality; 20 Nov. 1966; Hyde leg.; MKF • 2 specs; same locality; 1 Feb. 1966; Hyde leg.; ANIC • 1 spec.; same locality; 2 Feb. 1966; Hyde leg.; ANIC • 1 spec.; Queensland, Shire of Douglas, Daintree, 4 mi. S. of Daintree; 29 Oct. 1966; Britton leg.; edge of rainforest on dead leaves; ANIC • 2 specs; Queensland, Shire of Mareeba, Kuranda ; 16°49′ S, 145°38′ E; Dec. 1964; Brooks leg.; ANIC • 4 specs; same locality; Mar. 1950; Brooks leg.; ANIC • 1 spec.; Queensland, Shire of Mareeba, Kuranda, Black Mountain Road 10 mi. N of Kuranda; 16°46′ S, 145°40′ E; 8 Mar. 1969; Brooks leg.; ANIC • 1 spec.; Queensland, Tablelands Region, Ravenshoe ; 25 Dec. 1937; ANIC .

FIJI • 2 specs; Taveuni ; 10 Dec. 1923; Evans leg.; NHMUK • 1 spm; same data as for preceding; MKF • 2 specs; Rotuma Island, Noatau ; 12°29.9′ S, 177°2.82′ E; 26 Apr. 1971; Robinson leg.; at light; NHMUK .

INDONESIA • 6 specs; Java; NHMUK • 2 specs; Java; Wallace leg.; NHMUK • 1 spec.; Sumatra; Doherty leg.; NHMUK .

MALAYSIA • 8 specs; Pahang, Taman Negara ; 1–13 Mar. 1984; Jessop leg.; at light; NHMUK • 2 specs; same data as for preceding; MKF • 5 specs; Sarawak, Mt Matang ; Dec. 1913; Bryant leg.; NHMUK • 1 spm; same data as for preceding; MKF • 1 spec.; Sarawak, Muara Tuang, Kampung Quop ; Feb.–Mar. 1914; Bryant leg.; NHMUK .

PAPUA NEW GUINEA • 8 specs; Madang, R. Buru, 90 m NW of Lae; 1200 ft a.s.l.; 5°13′ S, 145°48′ E; 1 Oct. 1964; Bacchus leg.; at light; NHMUK • 1 spec.; Morobe, Lae ; 6°44′ S, 147°0′ E; 10 Dec. 1964; Bacchus leg.; NHMUK • 11 specs; Morobe, Finisterre Range, Budemu ; 4000 ft a.s.l.; 5°48′ S, 146°6′ E; 15–24 Oct. 1964; Bacchus leg.; at light; NHMUK • 1 spm; same data as for preceding; MKF • 12 specs; Morobe, Finisterre Range, Damanti ; 3550 ft a.s.l.; 5°48′ S, 146°6′ E; 2–11 Oct. 1964; Bacchus leg.; at light; NHMUK • 1 spm; same data as for preceding; MKF • 1 spec.; Morobe, Herzog Mountains, Vagau ; 4000 ft a.s.l.; 4–17 Jan. 1965; Bacchus leg.; NHMUK .

THAILAND • 1 spec.; Ranong; Doherty leg.; NHMUK .

VANUATU • 1 spec.; Malakula Island ; 16°15′ S, 167°30′ E; Mar.–Apr. 1929; Cheesman leg.; NHMUK • 2 specs; Espiritu Santo ; 15°15′ S, 166°50′ E; Aug. 1929; Cheesman leg.; NHMUK • 2 specs; same locality; Aug.–Sep. 1929; Cheesman leg.; NHMUK • 1 spm; same data as for preceding; MKF .

Distribution

Specimens of P. t-notatus have been recorded from Australia (Queensland), Fiji, Indonesia, Malaysia, Papua New Guinea, Thailand and Vanuatu.

Remarks

Psammoecus t-notatus is closely related to P. trimaculatus Motschulsky, 1858 and P. triguttatus Reitter, 1874 . Most specimens can easily be recognised by their distinct colouration/colour pattern. The determination of unusually coloured specimens requires examination of male genitalia. Psammoecus t-notatus differs from P. trimaculatus by the distinctly longer apical part of the parameres; it differs from P. triguttatus by the elongate, slender median lobe and the large, wide basal part of the tegmen.

Psammoecus t-notatus has a remarkably large area of distribution. As for other species of the genus, records from Malaise traps and at light suggest high mobility and a tendency to accumulate near human settlements. This, combined with an association with plant detritus and/or fungi, is likely to facilitate distribution by human trade of agricultural goods.

Figures

Fig. 4. Psammoecus t-notatus Blackburn, 1903. A–D. Holotype, ♀ (NHMUK). A. Habitus. B. Head. C. Pronotum. D. Left antenna. E–F. Specimen from Papua New Guinea, ♂ (NHMUK), aedeagus, ventral view. Scale bars: A = 1.0 mm; B–E = 0.5 mm; F = 0.2 mm.