Phausis riversi LeConte
Creators: name: Hodson, Alicia M.
name: Branham, Marc A.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Lampyridae
Phausis
Phausis riversi

description: Phausis riversi (LeConte, 1885)
(Figs 15; 18E; 22 Ee–Gg; 23C; 24K)
Lamprohiza riversi LeConte 1885: 20
Phausis riversi (LeConte): Olivier 1910: 3 (checklist); Fender 1962: 42; Fender 1966: 90; Keller and Branham 2018, 1–4
Diagnosis. Male. Phausis riversi can be distinguished by its congeners by the pronotum being flavus with a medial dark spot, pronotal hind angle bluntly denticulate (Fig. 18E), and paramere apices truncate (Fig. 22 Ff). This species looks similar to Phausis californica except Phausis riversi has longer antennae than P. californica (extending to the end of the metathorax versus extending to the middle of metathorax); apices of mandibles copper-colored; pronotum yellow as in Phausis californica except with medial dark brown spot on central pronotal disc(Fig. 18E); two elytral costae present; basal piece divergent versus entire, quadrate, and lacking pigmentation; median lobe lanceolate, with apex acutely rounded (less than 45 degrees); median lobe inner basal margin bifurcate; dorsal opening present (Fig. 22 Ee).
Redescription. Male (Figs. 18E; 22 Ee–Gg; 23C). Length 5.0–7.0 mm. Width 1.0– 3.2 mm. Color. Body dark brown; eyes black; mouthparts brown-yellow; antennae brown, scape and pedicel paler; pronotum flavus, central pronotal disc with brown spot located basal-medially; scutellum flavus; thorax brown; legs brunneous to flavus; coxae, trochanters, and bases of femora paler; lateral margins of elytra paler than elytral disc; abdomen brown with abdominal segments VII and VII posterior and lateral margins paler; photic organs absent on abdominal segments VI VII and VIII; pubescence aureus. Anterior vitreous areas (pronotal spots) present.
Head small and transverse (frontal view); vertex transversely concave with moderate punctures dorsally. Eyes small, separated, labium not obstructed postventrally. Mandibles normal (apices crossing), falcate, tapering gradually; incisor region length less than 1/2 of total length of mandible; outer margin convex versus straight as in other taxa (P. marina, P. nigra, P. skelleyi, and Phausis milleri); basal angle greater than 90 degrees dorsally. Maxillary palps with three palpomeres, last palpomere securiform. Labial palps reduced, with three palpomeres.
Antennae filiform, long, extending to approximately the middle of metathorax (Fig. 18E). Scape as long as pedicel. Pedicel approximately 1/3 the length of antennomere 3. Antennomere 3 as long as antennomeres 4 to 11. Antennomeres 6 to 10 becoming shorter, narrower, and more compressed towards apex. Antennomere 11 ovate at apex. Flagellomeres feebly compressed, becoming more compressed apically than basally; not as compressed as in Lucidota or Ellychnia; when viewed laterally, flagellomeres are wider than in ventral view. Sensorium present on the distal end of antennomere 11, semi-transparent, small, and subulate.
Pronotum about long as wide, semicircular (Fig. 18E); longitudinal median carina present, extending from base to apex of pronotum; lateral margins arcuate and slightly less reflexed than apical margin; all margins reflexed, equally explanate except for basal margin which is flattened toward the hind angles; basal margin weakly undulates, appears almost straight; hind angles bluntly denticulate. Central pronotal disc present; quadrate with lateral margins sinuate, shiny and finely sparsely punctate; dark brown to black spot present medially. Anterior vitreous areas (spots) present small (more than one width of spot between them), shape subreniform, punctate throughout.
Scutellum subspatulate; sides strongly sinuate and posterior apex round with longitudinal groove; surface sparsely, coarsely punctate, less so anteriorly (Fig. 18E).
Elytra well developed, slender; coarsely, moderately punctate, and becoming rugose medially and apically (Fig. 18E). Two costae present medially on each elytron; obscure, more prominent on humeral angles, then disappearing medially. Longitudinal elevated lines present weakly.
Venter. Thorax elongate and rhomboidal; Metathorax with posterior apex notched; medial line present; surface and finely sparsely punctate especially laterally. Tergal apicolateral angles strongly lobed. Abdominal segments VI and VII not bearing photic organs. Photic organ absent on abdominal segment VIII. Abdominal segments VII elongate, apical margin emarginated. Abdominal segment VIII length transverse, apical margin rounded.
Male Genitalia. Basal piece (dorsal view; Fig. 22 Ee) size longer than wide, quadrate and not sclerotized (translucent); distinct segments divergent (segments widely separated). Median lobe (dorsal view; Fig. 22 Ee) exceeds tips of parameres, lanceolate, acutely rounded (less than 45 degrees) at apex; parallel to parameres (Fig. 22 Ff); sensilla absent; dorsal inner-basal margins bifurcate; dorsal opening absent; longitudinal dorsal carina present; lateral line absent (lateral view); ventral opening present (Fig. 22 Gg), consisting of the apical fourth of medial lobe. Parameres (dorsal view; Fig. 22 Ee) robust, sub-parallel; inner lateral margins parallel; outer lateral margins parallel; apex truncate laterally; proximal flanges (extensions of parameres that curve or extend outward from inner margin) absent. Sensilla present, long, sparse along proximal apical margins (ventral view). Number of sensilla vary, if absent then a pore can be seen (Figs. 22 Ff-Gg; 23C).
Female. Unknown.
Larva. Unknown.
Eggs. Unknown
Etymology. Named after the collector Dr. J.J. Rivers by J. LeConte in 1885.
Specimens Examined. Type Material. Holotype (Figs. 18E; 24K). USA: CALIFORNIA: “Cal., ♂, L. riversi, Type No 2799”, 1 ♂ (MCZC).
Other material. USA: CALIFORNIA: ALAMEDA Co., Berkeley Hills, 23. VI.1984, Coll. J.B. Whitfield, 2 ♂ (EMEC); COSTA Co., Mt. Diablo State Park, Juniper Camp, 2900 feet, 27. VI.1964, 1 ♂ (CAS); DEL NORTE Co., Elk Valley, 4. VII.1965, Coll. Clark E. Ross, 1 ♂ (CAS); EL DORADO Co., Pyramid R.S., 17.VII.1948 1 ♂ (CAS); same except El Dorado Co., 8 mi S. Camino, 3. VII.1948, Coll. P.D. Hurd 1 ♂ (EMEC); same except 2mi N Placerville, 7. VI.1962, Coll. John T. Doyen, 1 ♂ (EMEC); same except Blodgett Forest, 13 mi E. Georgetown, 12. VII.1967, Coll. W.J. Turner, 1 ♂ (EMEC); same except Blodgett Forest, 13 mi E. Georgetown, 15 VII.1967, Coll. W.J. Turner, 1 ♂ (EMEC); same except Blodgett Forest, 13 mi E. Georgetown, UV light 30.VI.1981, Coll. J.A. Powell and J. DeBenedictis, 1 ♂ (EMEC); same except U.C. Blodgett Forest, 8 mi E. Georgetown, 25. VI.1970, Coll. C.O. Dudley, 1 ♂ (EMEC); same except Blodgett Forest, 5. VI.2001, Coll. K. Apigian, voucher, 1 ♂ (EMEC); HUMBOLDT Co., Arcata, 21. VII.1969, Coll. J.G. Todd, 2 males (EMEC); same except Arcata, 21. VII.1969, Coll. C. Slobodchikoff, 1 ♂ (EMEC); LAKE Co., Middletown, 19. VI.1949, Coll. Derham Giuliani, Derham Giuliani Collection, Accession No 1967, 1 ♂ (CAS); MARION Co., Inverness, 18. VII.1963, Coll. P.H. Arnaud 1 ♂ (CAS); MENDOCINO Co., Westport, 23. VII.1965, Lot 4, Coll. BF &JL Carr, J & B Carr Collection, 1 ♂ (CNCI); TRINITY Co., Forest Glen, 4. VII.1991, Lot 7, Coll. BF &JL Carr, J & B Carr Collection, 1 ♂ (CNCI); same except Forest Glen, 4. VII.1991, Lot 6, Coll. BF &JL Carr, J & B Carr Collection, 1 ♂ (CNCI); same except Forest Glen, 3. VII.1991, Lot 4 Coll. BF &JL Carr, J & B Carr Collection, 2 ♂ (CNCI); same except Forest Glen, 5. VII.1991, Lot 7, Coll. BF & JL Carr, 2 ♂, (CNCI); same except Forest Glen, 6. VIII.1991, Coll. BF & JL Carr, 1 ♂ (CNCI); SISKIYOU Co., 5 mi E of McCloud, 7. VII.1957, Coll. J. Powell, 1 ♂ (EMEC). OREGON: CURRY Co., Pistol River, 7. VII.1951, Coll. Borys Malkin, Kenneth M Fender Collection 1988 and 1992, Gifts to the California Academy of Sciences, 1 ♂ (CAS). MEXICO: BAJA CALIFORNIA NORTE: 2 mi N. Cataviña, 22/ 23.III.1987, Coll. J. Doyen, 1 ♂ (EMEC).
Distribution. Known throughout northern California to Oregon. One specimen was from Baja California, Norte, Mexico (Fig. 15).
Phenology. Occurs between June and early August. Specimen from Mexico collected in March.
Remarks. The holotype was originally described by LeConte in 1885 as Lamprohiza riversi. It was later synonymized and placed into the genus Phausis (Olivier 1910, Fender 1962, 1966). Holotype label data only says “Cal.” for California, but based on LeContes’ description the specimen was collected in Sonoma County by J.J. Rivers for whom the species in named after (LeConte 1885). Other localities where this species has been collected are as follows: CALIFORNIA: MARION Co., Mill Valley; SHASTA Co., Castle Crags and Burney Falls; TRINTIY Co., Carrville. Fender (1966) mentions that the texture of the metasternum is “finely sparsely granulate-punctate”, but specimens examined here (including the syntype) the texture is impunctate ventrally.
Variation. Identified. On some specimens examined, the dark brown spot on the central pronotal disc is not as obvious as on other specimens and appearing entirely flavus. Also, elytral costae can be variable. Costae appear obscure to present on some specimens. Syntype appears to not have costae, but instead weakly elevated longitudinal lines.
Biology. Unknown.
description: Published as part of Hodson, Alicia M. & Branham, Marc A., 2024, Revision and Phylogeny of the Genus Phausis (Coleoptera: Lampyridae) with the Description of Three New Species, pp. 1-52 in Zootaxa 5458 (1) on pages 39-40, DOI: 10.11646/zootaxa.5458.1.1, http://zenodo.org/record/11348272