Tychepsephus felix Waterhouse, 1876

Shepard, William D. & Barr, Cheryl B., 2023, A revision of the Chilean water penny genus Tychepsephus Waterhouse, 1876 (Coleoptera, Psephenidae, Eubriinae), with description of a second species and two larval morphotypes, and notes on other Chilean Psephenidae, ZooKeys 1164, pp. 23-61 : 23

Tychepsephus felix Waterhouse, 1876

Figs 7 , 8 , 12 , 13, 14 , 15, 16 , 17

Tychepsephus felix Waterhouse, 1876: 16 (original description). Philippi (1887: 665, catalog); Blackwelder (1944: 274, catalog); Artigas (1963: 8, larval description); Moroni (1985: 173, taxonomy, distribution); Ashworth and Hoganson (1987: 879, habitat, distribution); Elgueta and Arriagada (1989: 16, literature review); Jerez and Moroni (2006: 76, taxonomy, checklist); Lee et al. (2007: 527, phylogenetics), Zarges et al. (2019: 16, habitat).

Ectopria (Chilectopria) grandis Pic, 1947: 4, syn. nov.

Type locality.

The type locality was listed as only “Chili” on both the type specimen and in the species description. The female holotype specimen is housed in the NHMUK.

Type material.

Tychepsephus felix , Holotype female, pinned. Chile: "Type [white, circular label with red border] // Chili [blue, circular label // 668 // Tychepsephus felix , C. Waterh. (Type.) // NHMUK015011475" (Fig. 12 ). Deposited in the NHMUK. Ectopria (Chilectopria) grandis syn. nov., Holotype female, pinned. "Chili [green label] // Dascillide? [pale brown label] // type [pale brown label] // Museum Paris / Coll. M.Pic [blue-green label] // Chilectopria / s.g. grandis / n sp [pale brown label] // Chilectopria / grandis Pic // TYPE [red label] // HOLOTYPE [red label] // Tychepsephus / felix ♀ / W D Shepard // MNHN, Paris / EC17127" (Fig. 17 ). Deposited in the MNHN.

Other material examined.

Non-types (33). Chile: Region X, 3 km W of Nueva Braunau, Rio Colegual , 30 XII 2002 (WDS-A-1502) [on reverse], William D. Shepard, leg. (EMEC, 5, 2♂ 3♀) ; Chile: Region X, 9 km E Loncotoro, Pte. Colegual 2, 650' [198 m], 8 I 2003 (WDS-A-1519) [on reverse], William D. Shepard, leg. (11; EMEC, 7, 3♂ 4♀; MNNC, 4, 2♂ 2♀) ; Chile: Región X Lagos , Río Colegual 8 rd. km W Llanquehue, elev.700' [213 m], 41°16.51'S, 73°06.52'W, 8 Jan. 2003, C. B. Barr, sweeping willows and other riparian vegetation (EMEC, 5, 4♂ 1♀) ; Chile: Region X, 8 km SW Correntoso, Pte. Hondo [ Río Oroco], 420' [128 m], 31 XII 2002 (WDS-A-1504) [on reverse], William D. Shepard, leg. (EMEC, 1♀) ; Chile: Corral , Dec. 1905, R. Thaxter, MCZ (MCZC, 1♂) ; Chile: F. C. Bowditch Coll., “Bradytoma”, MCZ (MCZC, 1♂) ; Chile: Concepcion Pr , Estero Nonguen, 11 Noviembre 1996, Tomas Cekálovic (EMEC, 1♀) ; Chile: Chili, Germain , Sharp Coll. 1905-313, NHMUK015011806 (NHMUK, 1) ; Chile: Sharp Coll. 1905-313, Tycepsephus [sic] felix, C.O. Waterh ., Chili - Germain , NHMUK015011809 (NHMUK, 1) ; Chile: Puerto Varas , 16.xii.1926, S . Chile: Llanquihue prov. , F. & M. Edwards, B.M.1927-63, NHMUK015011807 (NHMUK, 1) ; Chile: Casa Pangue , 4-10.xii.1926, S . Chile: Llanquihue prov. , F. & M. Edwards, B.M.1927-63, Tychepsephus felix Waterh., M.I. Russell det. 1973, NHMUK015011808 (NHMUK, 1) ; Chile: Ancud. 17-19.xii.1926, S . Chile: Chiloe I., F. & M. Edwards, B.M.1927-63, NHMUK015011810 (NHMUK, 1) ; Chile: as above, NHMUK015011811 (NHMUK, 1); Chile: Ancud , 19.xii.1926, S . Chile: Chiloe I., F. & M. Edwards, B.M.1927-63, NHMUK015011812 (NHMUK, 1); as above, Tychepsephus felix Waterh., M.I. Russell det. 1973, NHMUK015011813 (NHMUK, 1) .

Differential diagnosis.

Males of T. felix (Figs 13 , 14 ) are much larger (4.6-5.2 mm long) than those of T. cekalovici sp. nov. (3.3-3.9 mm long); the pronotal cuticle is dark brown to black with pale lateral margins, with no yellow markings on disc; the elytral cuticle is dark brown or red-brown, with setal patterning only; the depressed frontal area between the eyes does not have an inverted Y-shaped sulcus; and abdominal ventrite 3 has a median, golden yellow setal patch that is not distinctly raised and does not extend the entire length of the ventrite.

In contrast, males of T. cekalovici sp. nov. (Figs 18 - 20 ) are considerably smaller than males of T. felix ; the pronotal cuticle is dark brown to black with pale lateral and basal margins, and a mediobasal yellow spot anterior and adjacent to the scutellar shield; the elytral cuticle is usually yellow-brown with dark markings in a zig-zag pattern, but may be mostly plain, without patterning; the depression between the eyes has a narrow, inverted Y-shaped sulcus; and abdominal ventrite 3 has a prominent, raised, golden yellow setal patch extending the full length of the ventrite.

The aedeagi (Figs 14 , 19 ) of the two species are clearly different. In T. felix (Fig. 14 ), the parameres have straight lateral margins and only slightly curved medial margins, and the apices are narrow. In T. cekalovici sp. nov. (Fig. 19 ) the parameres have curved lateral and medial margins, and the apices are broad.

Females of T. felix (Figs 15 , 16 ) are much larger (4.3-5.7 mm long) than those of T. cekalovici (3.3-3.9 mm long); the elytral cuticle is brown, without yellow patterning except for variable, slightly paler areas near the base; and the pronotal disc has no yellow markings. Tychepsephus cekalovici sp. nov. females (Figs 21-23 ) usually have elytra with transverse yellow bands in a zig-zag pattern, but those without may be distinguished by a mediobasal yellow spot on the pronotum anterior to the scutellar shield. The ovipositors are similar.

Original type description, female

(Fig. 12 ). Waterhouse (1876) described the species in Latin, as was the custom at the time. An English translation follows:

Ovate, convex, glossy, dark pitch black, bronzy; fine, short, grey pubescence. Head yellow, rather wide, narrow between antennae, eyes prominent, antennal bases yellow. Thorax slightly convex, densely finely punctate, length twice width, suddenly narrowed anteriorly, frontal margin slightly lobed in middle, both sides sinuate, anterior angles somewhat prominent, sides slightly rounded behind middle, posterior angles almost right-angled, edges narrowly yellow. Scutellum yellow, apex acute. Elytral bases slightly wider than thorax, enlarged posteriorly, arched at apex, narrowed, convex, more clearly finely punctured, dorsum depressed; humeri obtuse, with edges narrowly yellow. Venter with densely grey pubescence, tarsi pitch black-yellow. Length 2.75 lin., width 2 lin.

Waterhouse (1876) added two sentences, in English: "The thorax is at the base nearly straight next to the scutellum, but is broadly sinuate on each side, so that at first sight it appears only bisinuate. Epipleural fold of the elytra is broad at the base, gradually narrowing to the apex, channeled posteriorly."

Redescription based on new material.

Male (Figs 13 , 14 ). Body: covered with short black setae and thick, moderately long yellow setae; yellow setae forming patterns on elytra. Cuticle with closely spaced punctures, punctures finer ventrally. Pronotum black with yellow margins. Elytra dark brown or red-brown with yellow lateral margins. Length 4.6-5.2 mm (n = 6), width 2.8-3.5 mm (n = 5). Head: covered with moderately long, yellow setae. Vertex between eyes wider than diameter of an eye. Frons deflexed at 90° angle from vertex, with a contiguous pair of broad, moderately deep depressions between eyes. Frontoclypeal suture absent. Clypeus trapezoidal, longer than wide, widest apically; clypeus noticeably raised; anterolateral angles curved beneath antennal bases. Maxillary palpus with four palpomeres; palpomeres 1-3 yellow to yellow-brown; 4 yellow-brown to dark brown, obliquely hatchet-shaped, weakly curved at apex. Labial palpus with three palpomeres; palpomeres 1-2 yellow; 3 yellow-brown to dark brown, with apex truncate to weakly curved; glossae and paraglossae split, apically acicular. Antenna weakly serrate, with 11 antennomeres; 1 longest, cylindrical, yellow; 2 shortest, yellow-brown; 3-11 dark brown, each widest apically. Antennal base encircled by raised margin. Eye large, bulbous, finely faceted. Pronotum: twice as wide as long, widest just anterior to base; anterior margin convex between anterior angles; anterior angles obtuse, broadly rounded, projecting anteriorly, clasping eyes; lateral margins finely sculptured with shallow notches, narrowly explanate, straight from anterior angles to basal 1/3 then curved to posterior angles; posterior angles square; posterior margin crenulate, nearly straight between posterior angles almost to scutellar shield, then curved posteriorly, straight adjacent to scutellar shield; disc depressed near anterior angles, convex at middle, flattened basomedially. Scutellar shield: pentagonal, flat, depressed between elytra; densely covered by moderately long, yellow setae; anterior margin crenulate; apex acute. Elytra: conjointly longer than wide, widest at ~ 1/3 the distance from apices, wider than pronotum; each with anterior margin crenulate; lateral margin smooth, narrowly explanate; humerus prominent with adjacent medial depression; area adjacent to lateral margin in anterior 1/3 with a wide, moderately deep depression; disc much more convex at posterior 1/2. Setae largely absent from oval area posterior to middle and round area at apical 1/4 near suture; setae sparse near base. Epipleuron widest below humerus, narrowed posteriorly; channeled adjacent to abdomen, channel becoming deeper towards apex. Metathoracic wings: macropterous. Prosternum: wider than long; cuticle brown, densely setose; anterior margin projecting to cover mouthparts with a short chin piece; prosternal process long, narrow, extending well past procoxae to anterior third of mesosternum, elevated above rest of prosternum; disc with shallow, longitudinal, median ridge. Mesoventrite: brown; wider than long, extending between mesocoxae; mesoventral cavity deep to receive prosternal process. Metaventrite: wider than long, cuticle black; disc convex lateral to discrimen; deep fossa at junction of discrimen and metakatepisternal suture; posterior margin weakly sinuate anterior to metacoxae. Legs: completely covered with dense, yellow setae; similar, except procoxa and mesocoxa globular, metacoxa widely transverse; femur and tibia usually darker than tarsus; tibia and tarsus long and narrow, tarsus longer than tibia; tarsus densely covered with pale setae; claws long, slender. Abdomen: brown, densely setose; with five weakly convex ventrites; ventrites 1-4 short, ventrite 5 longest; ventrites 1-3 with lateral margins notched medially; ventrite 3 with a dense patch of coarse, golden yellow setae covering the posteromedial 1/2-2/3 of the disc. Aedeagus: (Fig. 14 ) more than twice as long as wide; phallobase vase-shaped, narrow at base, wide at apex; parameres stout, much longer than penis, lateral margins straight at basal 2/3 then gradually curved inward at apical 1/3, medial margins only slightly curved, parameres each narrowed toward a rounded apex; penis tapered, apex broadly rounded, basally with two apophyses. Female (Figs 15 , 16 ) similar to male except: frons with an inverted Y-shaped suture between eyes; setation of dorsum less dense except for scutellar shield; cuticle of humeri and elytral bases sometimes paler than disc; tarsi less densely setose; abdominal ventrite 3 without a dense patch of yellow setae. Ovipositor: (Fig. 16 ) with baculus nearly twice as long as gonocoxite; baculus almost twice as long as wide, strap-like, wider apically; each proximal gonocoxite triangular, distal gonocoxites separate basally then converging to meet apically, apices obliquely truncate; each gonostylus long and narrow, half as long as distal gonocoxite.

Variation.

The sizes of males and females overlap: males, 4.6-5.2 mm long (n = 6), 2.8-3.5 mm wide (n = 5); females 4.3-5.7 mm long (n = 10), 2.9-3.7 wide (n = 5); but the largest specimens are female. Most males (Fig. 13a ) have an elytral pattern with moderately dense setae surrounding mostly glabrous areas; most females (Fig. 15a ) have no pattern and are more sparsely setose. Females (Fig. 15b ) lack the dense patch of yellow setae on abdominal ventrite 3 that is present in males (Fig. 13b ).

Etymology.

Waterhouse (1876) did not explain the trivial name. However, felix (L.) means happy or prosperous.

Geographic distribution.

Tychepsephus felix is known only from Chile. Adults have been collected mainly in Región X (Los Lagos), but also in regions VIII ( Bío Bío), IX ( Araucanía), and XIV (Los Ríos) (M. Elgueta, in litt.), in both the Andean and the coastal mountain areas (Fig. 7 ). The greatest number of adults collected by the authors was at Río Colegual west of Puerto Varas (Fig. 8 ).

Habitat.

Tychepsephus felix adults were found in habitats as described for the genus. Specimens were collected by sweeping marginal vegetation along streams during the austral summer (Fig. 8b ).

Associated dryopoid taxa.

Elmidae : Larainae : Hydora annectans Spangler & Brown, 1981, H. lenta Spangler & Brown, 1981; Elminae : Austrolimnius Carter & Zeck, 1929, Luchoelmis Spangler & Staines, 2004, Neoelmis sissicollis (Germain, 1892). Both T. felix and T. cekalovici sp. nov. occurred at Río Colegual.

Type remarks.

The species was described by Waterhouse (1876) from a single female type (Fig. 12 ) which is in the NHMUK along with eight non-type specimens subsequently acquired. The type was originally pinned, breaking the right elytron just posterior to the pin. Subsequently, the specimen was removed from the pin and card-mounted. Missing parts include the following: left antenna without antennomeres 3-11; left foreleg; right hind leg; tarsi on all legs except left hind leg; and tarsomere 5 on the left hind leg. One leg, without the tarsus, is in a gelatin capsule pinned below the carded specimen.

The female type of Ectopria (Chilectopria) grandis Pic, 1947 (Fig. 17 ), housed at the MNHN, was examined and found to be synonymous with Tychepsephus felix Waterhouse, 1876. Pic described Chilectopria as a subgenus of Ectopria : " Chilectopria s. g. de Ectopria. " Subsequently, Chilectopria sometimes has been cited incorrectly as a genus, rather than a subgenus, likely because the heading and description occur on different pages ( Pic 1947: 3-4). Contributing to this error, the type specimen also lacks " Ectopria " on the identification label. The genus Ectopria is a Holarctic element.

Figures

Figure 7. Map of Chile with enlarged section showing the geographic distribution of species-verified adult Tychepsephus specimens: T. cekalovici, yellow triangles; T. felix, violet squares; both species, red circles.

Figure 12. Tychepsephus felix, female type specimen a dorsal view b ventral view c specimen data labels. Images provided by Keita Matsumoto (NHMUK).

Figure 17. Chilectopria grandis, female type specimen a dorsal view b lateral view c ventral view d specimen data labels. Images provided by Christophe Rivier (MNHN).

Figure 20. Tychepsephus cekalovici sp. nov., male dorsal habitus showing color pattern variation a length 3.3 mm b length 3.5 mm c length 3.5 mm.

Figures 8 - 11. Tychepsephus habitat 8 Rio Colegual, T. cekalovici type locality a stream with riffle-pool morphology flowing through a mixture of forest and pasture land b streamside shrubby vegetation, adult habitat 9 Rio Contaco 10 stream at Puente El Avion 11 tributary Rio Blanco.

Figures 13, 14. Tychepsephus felix, male 13 habitus a dorsal view b ventral view; length 5.0 mm 14 aedeagus a dorsal view b lateral view c ventral view.

Figures 15, 16. Tychepsephus felix, female 15 habitus a dorsal view b ventral view; length 4.2 mm 16 ovipositor, dorsal view.

Figures 18, 19. Tychepsephus cekalovici sp. nov., male 18 habitus a dorsal view b ventral view; length 3.2 mm 19 aedeagus a dorsal view b lateral view c ventral view.

Figures 21 - 23. Tychepsephus cekalovici sp. nov., female 21 habitus a dorsal view b ventral view; length 4.4 mm 22 dorsal color pattern variation; length 4.3 mm 23 ovipositor, dorsal view.