Thortus amoenus ( Broun, 1912 )

Thortus amoenus ( Broun, 1912)

( Fig. 6 View Fig )

Cryptophagus amoenus Broun, 1912: 423 .

Thortus amoenus : GIMMEL & LESCHEN (2022: 106).

Material examined (58; AMNZ, BMNH, FRNZ, NZAC). NORTH ISLAND: TO: 1 ( FRNZ), Pukemako, 12 Feb - 19 Mar 2020, 37°51.648′S, 175°32.027′E; 1 ( FRNZ), Pukemako pitfall 2 14 Dec - 22 Feb 2023, C.Wardhaugh, 37°51.648′S, 175°32.027′E; 1 ( BMNH),Waimarino, Jan 1911, [39°26.368′S, 175°7.732′E]. GB: 1 ( FRNZ), Putere, Site 8495, 16 Jan 13 - 13 Feb 2013, E M. Scott, 38°56.39′S, 176°55.004′E. RI: 1, Vinegar Hill Reserve, Nov 1999, tawa, titoki, mahoe forest remnant, G.M. Coombe, 39°56.220′S, 175°38.35′E, AMNZ 34211; 1, Wharite Summit, 23 Oct 1993, J. Nunn Collection, [40°15.274′S, 175°51.454′E], NZAC 04238460. WI: 1, Bruce Park, SH1, 3-6 Feb 2000, rimu/tawa forest,J.W.Early, 39°57.555′S, 175°32.083′E, AMNZ 27647;1, Manawatu Gorge, near Woodville,Manawatu Dist., North Is, 12.12.1948, leaf mould,

A. E.Brookes, 40°18.96′S, 175°48.96′E, NZAC 04069899. WA: 2, Puketoi Range, near Mount Butters, 28 Jan 2008, forest patch in gully below road, sifted leaf litter and rotten wood, K. Marske, R. Leschen, T. Buckley, 40°33.723′S, 176°3.364′E, KM271, NZAC 04234449, NZAC 04234522;2, Sutherland Vehicle Track, Aorangi Range, 24 Jan 2008, sifted wood and leaf litter in secondary forest on former grazing land, K. Marske, R. Leschen, T.Buckley, 41°25.239′S, 175°21.551′E, KM245, NZAC 03019393, NZAC 03026611; 1, Waepae Forest, Puketoi Range, 28 Jan 2008, dead wood along disused forest track, K. Marske, R. Leschen, T. Buckley, 40°33.210′S, 176°1.893′E, KM268, NZAC 03019561. WN: 1, Balance Bridge Reserve, 3 Jan 1975, litter, J.C. Watt, [40°20.244′S, 175°49.1′E], NZAC 04234429; 1, Catchpool Loop Walk, Catchpool Stream, Rimutaka Forest Park, 22 Jan 2008, sifted wood and leaf litter, K. Marske, R. Leschen, T. Buckley, 41°21.067′S, 174°55.964′E, KM233, NZAC 03020596; 1, Kaitoke, Pakuratahi Forks, 18 Jul 1993, in Cortaderia litter, J. Nunn Collection, [41°3.374′S, 175°11.698′E], NZAC 04234613; 1, Kapiti Island, [40°51.617′S, 174°54.317′E], NZAC 03019658; 1, Karori Reservoir, 16 Oct 1994, forest leaf litter, J. Nunn Collection, [41°18.408′S, 174°44.354′E], NZAC 04234457; 1, Keith Gorge Reserve, Silverstream, 17Apr 1995, leaf litter, J. Nunn, [41°8.254′S, 174°58.561′E], NZAC 04235060; 1, Khandallah Domain, 5 Apr 1994, decayed wood, J. Nunn [41°14.721′S, 174°47.815′E], NZAC 04234450; 2, Levin,Kimberley Reserve, 6 Nov 1980, litter, C.F. Butcher, [40°58.179′S, 175°15.647′E], NZAC 04234435, NZAC 04234437; 1, Manawatu District Balance Bridge, 19 Dec 1948, leaf mould, A.E. Brookes Collection, [40°20.244′S, 175°49.1′E], NZAC 04234434; 1, Paraparaumu, Nikau Reserve, 3 Oct 1983, J. Nunn Collection, [40°54.581′S, 175°2.563′E], NZAC 04234432; 1, Ruahine Range, Wharite Peak, 19 Nov 2015, forest litter, J. Nunn, [40°15.274′S, 175°51.454′E], NZAC 04235090; 1, Tararua Forest Park 4 km along Waiotauru Road, 16 Nov 1991, J. Nunn Collection, [40°58.179′S, 175°15.647′E], NZAC 04234440; 1, Tararua Forest Park, Fields Hut, 8 Dec 1953, lichen sample, B.A. Holloway, [40°58.179′S, 175°15.647′E], NZAC 04234611; 1, Tararua Forest Park, Waiotauru Road, 25 Aug 1998, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234430; 1, Tararua Forest Park, Waiotauru Road, 4 May 1999, E.Spurr, [40°58.179′S, 175°15.647′E], NZAC 04114146; 1, Tararua Forest Park,Waiotauru Road, 11May 1999,E.Spurr,[40°58.179′S, 175°15.647′E], NZAC 04114156; 2, WN, Tararua Forest Park, Waiotauru Road, 25 May 1999, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234442, NZAC 04272533; 1, Tararua Forest Park, Waiotauru Road, 1 Jun 1999, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234615; 1, Tararua Forest Park, Waiotauru Road, 7 Jun 1999, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234438; 1, Tararua Forest Park, Waiotauru Road, 22 Jun 1999, E.Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234527;2, Tararua Forest Park,Waiotauru Road, 5 Jul 1999, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234451, NZAC 04234542; 2, Tararua Forest Park, Waiotauru Road, 20 Jul 1999, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234475, NZAC 04272534; 1, Tararua Forest Park, Waiotauru Road, 25 May 2000, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234577; 3, Tararua Forest Park, Waiotauru Road, 15 Jun 2000, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234553, NZAC 04234556, NZAC 04234632; 1, Tararua Forest Park, Waiotauru Road, 20 Jun 2000, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234483; 1, Tararua Forest Park, Waiotauru Road, 27 Jun 2000, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234609; 2, Tararua Forest Park, Waiotauru Road, 11 Jul 2000, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04114147, NZAC 04234627; 1, Forest Park, Waiotauru Road, 18 Jul 2000, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234555; 2, Tararua Forest Park, Waiotauru Road, 15 Aug 2000, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04114154, NZAC 04234528; 1, Tararua Forest Park, Waiotauru Road, 21 Aug 2000, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234541; 1, Tararua Forest Park, Waiotauru Road, 29 Aug 2000, E. Spurr, [40°58.179′S, 175°15.647′E], NZAC 04234642; 2, Tinokori Hill, 13 Jun 1991, decayed wood, J. Nunn Collection, [41°16.047′S, 174°46.630′E], NZAC 04234453, NZAC 04234517; 1, Wiltons Bush, 4 Jul 1992, J. Nunn Collection, [41°15.991′S, 174°45.164′E], NZAC 04234456. SOUTH ISLAND: SD: 1, Port Underwood Saddle, NE Picton, 10 Dec 2007, sifted leaf litter and woody debris, K. Marske, J. Allwood, [41°16.961′S, 174°6.593′E], KM094, NZAC 03018835. MB: 1 ( FRNZ), Blenheim, Site BZ102 - East D. Henley 11 Jan - 7 Feb 2011, 41°22.204′S, 173°58.687′E.

area on disc of pronotum; E – aedeagus, dorsal view; F – parameres, dorsal view; G – distipenis, dorsal view.

Diagnosis. Thortus amoenus is recognized by having the parasutural stria complete and the eye having 10–12 facets. It can be distinguished from T. sulcatus by the lack of a median pronotal impression and from T. lobatus by the wider clypeal constriction.

Redescription. Length 1.17–1.50 mm. Colour of body dark to light reddish-brown, mouthparts, legs, and antennal club lighter (sometimes entire antenna). Microsculpture absent, surfaces of body semiglabrous. Dorsal setae silvery-gold, sparse, dual, consisting of very long decumbent and scattered erect and suberect setae. Ventral surfaces with shorter, suberect setae; punctation ovate, mesoventrite foveolate, central disc of metaventrite with punctures larger and more impressed than those of prosternum, punctation of abdominal ventrites 1 to 4 smaller than those on metaventrite, punctation on ventrite 5 denser with a well-defined patch of posteriorly-directed setae. Head lengthened, with relatively long gena about 1.5 times length of antennomere 1; frons constricted, narrowed to a width about half the length of antennomere 1; supra-antennal ridge with well-developed rim, bead present; vertex delimited anteriorly by a transverse crenulate line, anterior surface nearly impunctate and glabrous, posterior surface with broad, shallow, foveolate punctures; gular punctation deep, ovate, diameters similar to those on side of head. Eye consisting of 10–12 facets. Antennomere 2 cylindrical, slightly wider than long, antennomere 3 subconical, longer and as wide as 2 and longer and slightly wider than 4, proportions of antennomeres 4–8 equal, antennomere 9 wider than 8 and narrower than 10 and 11, antennomere 10 transverse and as wide as 11, antennomere 11 longer than 10, shorter than 9 and 10 combined. Pronotum subquadrate, pronotal length/width ratio ~1.04, widest just behind middle; anterior margin straight; anterior angles right, not protruding or acute; lateral edges more or less parallel and not gradually converging anteriorly, curved posteriorly; pronotal disc with punctures regular, uniform, separated by a distance of up to 1 times their diameter, rarely with a median glabrous strip; median impression absent; not or weakly transversely depressed at base; basomedial macropuncture absent; posterolateral angles obtuse, rounded, not projecting posteriorly; posterior margin sinuate with a weak scutellar lobe. Prosternal process with well-developed lateral marginal beads, without longitudinal depression medially, process weakly widened posteriorly behind procoxae, apex rounded, width subequal to width of procoxa, 0.46 times shorter than length of prosternum; procoxal cavity without anterolateral notch. Scutellar shield rectangular, 3.3 times wider than long. Elytra about 1.85 times as long as combined width, about 1.24 times width of pronotum at greatest width, about 2.18 times length of pronotum; setation dual, consisting of very long, decumbent setae and fewer suberect setae; humeral plica present; parasutural stria present, complete, interspace setose; punctation similar to pronotum, but separated by a distance of up to 1–3 times their diameter. Metaventrital process with anterior margin rounded, marginal bead connected at middle. Tarsi moderately slender, 5-5- 5 in female, 5-5- 4 in male, male pro- and mesotarsomeres 1–3 lacking well-defined tenent setae; mesotarsomeres 1–3 of subequal lengths, mesotarsomere 5 equal to tarsomeres 1–4 combined. First abdominal ventrite with postcoxal lines acuminate and parallel, extending to mid-length of sclerite; intercoxal process rounded at apex. Aedeagus with relatively long parameres articulated to phallobase, paramere about 3 times as long as wide; apices asetose, with short, membranous extensions; basipenis about 4.73 times as long as distipenis; distipenis about 1.33 times as long as wide, lateral lobes not separated, basal plate absent; internal sac with a pair of short slender endophallites that are anteriorly widened and spatulate.

Distribution. North Island: TO, GB, RI, WI, WA, WN. South Island: SD, MB ( Fig. 21 View Fig ).

Remarks. Thortus amoenus is distributed in the southern portions of North Island. It is found in leaf litter, leaf mould, and decayed wood. Several specimens were collected in traps baited with 1080 (sodium fluoroacetate), a mammal- -specific poison (e.g., SPURR & BERBEN 2004).

Some specimens have a medial glabrous strip on the pronotal disc, which is also a variation present in specimens of T. lobatus .

The holotype (BMNH), collected from Makatote (Tongariro), was confirmed in LESCHEN & GIMMEL (2012). A second BMNH specimen labelled by Broun with his number (3229) also had attached to it handwritten labels with the combination ‘ Pithortus amoenus ’ and collected from Waimarino which refers to place names in the central North Island ranging from Hawkes Bay westward to Tongariro.