Orthocis platensis Brèthes, 1922

Lopes-Andrade, Cristiano, Araujo, Lucimar Soares De & Sandoval-Gómez, Vivian E., 2020, Redescription of Orthocis platensis Brèthes, 1922 (Coleoptera: Ciidae) and the first records of the species from Brazil, Zootaxa 4810 (1), pp. 153-160 : 154-155

Orthocis platensis Brèthes, 1922

Figures 1–18

Orthocis platensis in Brèthes (1922: 302–303) ; Lawrence (1971: 484, list of Orthocis species). Type locality: “Tigre (prov. de. Buénos-Ayres)”, Argentina.

Cis dilleri in Abdullah (1973: 211 , unnecessary replacement name for Orthocis platensis Brèthes, 1922 , not Xestocis platensis Brèthes, 1922 ).

Presumed type ( Figs. 9–11 ). Glued on small card, venter concealed ( MACN) “ J. Brethes Buenos Aires 8.I.1907 [handwritten] \ Orthocis platensis Brèthes [handwritten] \ ES TIPO [handwritten; red label]” .

Diagnosis. It differs from other South American Orthocis species in the elytral surface been mostly lighter than pronotal disc. Orthocis elguetai is similar in the bicolored body, but it’s comparatively more elongate (TL/EW 2.80– 4.00), with conspicuous dorsal vestiture, and elytra bearing a M-shaped dark mark anteriorly and two V-shaped dark marks posteriorly. Orthocis platensis is very similar to O. apicipennis , but in the latter only the posterior portion of elytra is light coloured and the pronotum has smooth interspaces of punctures.

Redescription of females. Body elongate ( Figs 1–9 , 12, 14 ); dorsal and ventral vestiture of minute decumbent setae; dorsal setae about as long as one puncture-width; ventral setae longer than dorsal ones; dorsal punctures gradually narrowing to bottom, fine under diffused light ( Figs 5–8 ), coarse under direct incident light ( Figs 9–10 ); ventral punctation fine; dorsum bicolored ( Figs 1 , 5–9 ), head and pronotum mostly dark brown, elytra mostly pale (contrast of light to dark areas varies between specimens, but their shape is similar); venter mostly dark brown ( Fig. 3 ); antennae, palpi and tarsi light yellowish brown. Head barely visible from above ( Figs 1 , 12 ); dorsum convex; punctures separated from each other by about 3 puncture-widths, interspaces shallowly microreticulate; anterior edge ( Figs 7 , 12 ) straight at middle, corners broadly rounded, slightly explanate; labrum visible from above ( Figs 5–7 ). Mouthparts ( Fig. 15 ) with prementum subtrapezoidal; labial palpi 3-segmented, the first 0.34X as long as the second and 0.57X as long as the apical, apical 2.3X as long as wide. Gula ( Fig. 15 ) 0.55X as wide as head. Antennae ( Fig. 16 ) 10-segmented, as follows (in mm, left antenna measured in specimen from Serra do Brigadeiro): 0.05, 0.04, 0.05, 0.03, 0.02, 0.02, 0.01, 0.04, 0.04, 0.07 (FL = 0.24, CL = 0.16, CL/FL = 0.66). Eyes subovoid, coarsely facetted, each with about 80 ommatidia; GW = 0.15. Pronotum punctures separated from each other by about 2–3 puncture-widths, interspaces shallowly microreticulate ( Fig. 13 ); posterior portion with narrow impunctate longitudinal midline; anterior edge broadly rounded; anterior corners rounded; lateral edges slightly explanate, not crenulated, usually visible for their entire lengths when seen from above ( Figs 1 , 5–8 , 12 ); surface mostly dark brown, except for large pale area at anterior portion and small light-coloured area close to scutellar shield. Scutellar shield ( Fig. 13 ) dark brown; BW = 0.10. Elytra punctation single (but additional minute punctures visible under SEM, Fig. 13 , indiscernible under optical instruments); interspaces of punctures smooth ( Fig. 13 ); surface mostly pale ( Fig. 5 ) to light brown ( Fig. 6 ), except for dark brown irregular areas along basal two-thirds of lateral edges ( Fig. 2 ) and dark brown line along elytral suture ( Figs 5–6 ). Hind wings fully developed. Hypomera ( Fig. 14 ) microreticulate; punctures sparse, barely discernible. Prosternum ( Figs 14, 17 ) slightly tumid at middle, not carinate; surface similar to hypomera, except for median smooth area with comparatively more setae. Prosternal process ( Figs 14, 17 ) short, slightly smaller than prosternum before coxae; sides sinuous, apex broadly rounded, bent inwardly. Tibiae ( Fig. 14 ) not expanded to apex; outer apical angle rounded. Metaventrite ( Fig. 14 ) punctures fine, sparse, interspaces microreticulate on laterals, smooth on disc; discrimen very shallow, barely discernible. Abdominal ventrites ( Fig. 14 ) punctures and interspaces similar to those on metaventrite; length of ventrites (in mm, from base to apex at the longitudinal midline; specimen from Serra do Brigadeiro) as follows: 0.29, 0.13, 0.11, 0.10, 0.13; first abdominal ventrite devoid of sex patch (but all examined specimens presumably females). Female abdominal terminalia ( Fig. 4 ; measurements in specimen from Nova Teutônia): gonocoxites 0.31 mm long, with four ventral lobes; gonostyli 0.04 mm long (not considering apical seta), straight, parallel-sided, 4.2X as long as wide, inserted apically at gonocoxites; paraprocts 0.45 mm long, 1.45X as long as gonocoxites; baculi of paraprocts and proctiger long and slender; spiculum ventrale curved, 0.75 mm long (linear measurement).

Males. Unknown.

Measurements. Measurements in mm (n = 22): TL 1.55–2.35 (1.96 ± 0.18), PL 0.50–0.80 (0.66 ± 0.08), PW 0.60–0.95 (0.80 ± 0.09), EL 1.05–1.55 (1.31 ± 0.12), EW 0.60–1.10 (0.86 ± 0.14), GD 0.50–0.75 (0.63 ± 0.07). Ratios: PL/PW 0.72–0.93 (0.82 ± 0.06), EL/EW 1.18–2.00 (1.54 ± 0.21), EL/PL 1.73–2.33 (2.00 ± 0.18), GD/EW 0.59–0.86 (0.74 ± 0.09), TL/EW 1.82–2.86 (2.31 ± 0.28).

Other specimens examined. Argentina: 1 ( MNHN) “Rep. ARGENTINA Prov. Buenos Aires iii. 1893 C. Bruch \? [unreadable] W. ou sp. près [handwritten] \ Cis [handwritten] \ Pic [handwritten] \ Orthocis platensis Bréthes [handwritten] Det. J. F. Lawrence \ MNHN Paris”; 3 ( MACN) “REP. ARGENTINA Prov. Buenos Aires [printed] III. [handwritten] 189 [printed] 3 [handwritten] C. Bruch ”, one mounted on card, lacking head and prothorax and additionally labelled “ Cis Bauri W [sic; may refer to Cis baeri Pic ] oú sp. près. [handwritten]”, the other two in another pin, mounted at the same card . Brazil: 13 ( CELC, 3 dissected females) “BR: MG Serra do Brigadeiro Pico do Boné, ix.2000 leg. E. C. Stehling ”; 1 ( CELC) “BR: RJ Teresópolis P. N. Serra dos Órgãos 14.xi.2011, leg. L. S. Araujo \ Código: Trans.: 1, Parcela: D, Fungo: 2 [ Hymenochaete sp.]”; 8 ( DZUP) “Brasilien Nova Teutonia 27º 11’ B. 52º 23’ L. Fritz Plaumann XII 1980 300-500 m ” additionally labelled with collection numbers “ DZUP 273664 ” to “ DZUP 273671 ”; 1 ( CELC) “ Nova Teutonia Santa Catarina BRAZIL XI-65 Fritz Plaumann ”; 1 ( CELC) “BRAZIL: Santa Catarina, Nova Teutonia Sept F. Plaumann ”; 5 (3 FMNH; 2 dissected females CELC) “Nova Teutonia Santa Catarina BRAZIL March F. Plaumann ”, one additionally labelled “ Orthocis 591 platensis Brethes ”. All specimens additionally labelled “ Orthocis platensis Brèthes, 1922 det. C. Lopes-Andrade, 2019” .

Host fungus. Hymenochaete sp. ( Hymenochaetaceae ), one non-breeding record.

Distribution. The species is here recorded from the following localities: Pico do Boné at Araponga, state of Minas Gerais, and Parque Nacional da Serra dos Órgãos at Teresópolis, state of Rio de Janeiro, both in Southeast Brazil; and Nova Teutônia, state of Santa Catarina, in South Brazil ( Fig. 18 ).

Comments. Brèthes (1922), in the description of O. platensis , wrote in French “J’obtins cette espèce aux îles du Tigre (prov. De Buénos-Ayres), en mars 1907 ” and repeated the information in Spanish “Obtuve esta especie en las islas del Tigre (prov. De Buenos Aires), en marzo de 1907”, and both can be translated to English as “I obtained this species in the Tigre islands (province of Buenos Aires), in March 1907 ”. He has not mentioned how many specimens were collected. The specimen labelled as type, deposited in the MACN ( Figs 9–11 ), lacks any reference to the Tigre islands in labels and is dated “ 8.I.1907 ”. We’re assuming it belongs to the type series, because it was collected by the author in 1907 and it’s dated two months before what’s mentioned in the description. Therefore, we can assume Brèthes had it in hand while describing the species. Because of this incongruence between labels and description, we have decided not to designate it as lectotype. Orthocis apicipennis is a very similar species and initially we were tempted to synonymize it with O. platensis . However, after careful examination of all specimens determined as O. platensis , including the presumed type, and comparison to the type of O. apicipennis , we have concluded the features mentioned in the diagnosis above are sufficient to separate these species. There was no sign of external variation that could be linked to male secondary sexual features. The dissected specimens, and the ones with exposed abdominal terminalia, were all females. Therefore, we are presuming here, certainly with some risk, that the species is currently known only from females. It shall be noted that males and females of Orthocis species are usually indiscernible externally ( Lawrence 2016). The examined Brazilian O. platensis are the first records from the country and considerably extend the geographical distribution to the north. The single available host fungus record is for the specimen collected in Hymenochaete sp. ( Hymenochaetaceae ) at Teresópolis, but that is not a breeding record.

Figures

FIGURE 18. Known occurrences (circles) of Orthocis platensis Brèthes.

FIGURES 1–4. Orthocis platensis Brèthes from Nova Teutônia, South Brazil. 1. Dorsal view. 2. Lateral view. 3. Ventral view. 4. Part of female terminalia showing paraprocts (pp), proctiger (pt), gonocoxites (gc) and gonostyli (gs). Scale bars: 0.5 mm (1–3), 0.2 mm (4).

FIGURES 5–11. Images of Orthocis platensis Brèthes showing colour variation of dorsum (5–9), and the presumed type deposited in the MACN (dorsal, 9; lateral, 10) and its labels (11). Images 5–8 were taken under diffused light, whereas images 9–10 were taken under direct incident light, leading to differences in the perception of the shape of punctures (see text). 5. Specimen from Serra do Brigadeiro (Araponga, Southeast Brazil). 6. Teresópolis (Southeast Brazil). 7. Nova Teutônia (South Brazil). 8–10. Buenos Aires (Argentina). Scale bars: 0.5 mm (5–9), 1.0 mm (10), 5.0 mm (11).

FIGURES 12–17. SEM-VP images of Orthocis platensis Brèthes from Serra do Brigadeiro (Araponga, Southeast Brazil). 12. Dorsal view. 13. Scutellar shield surrounded by part of pronotum and elytra. 14. Ventral view. 15. Ventral view of part of head, showing buccal apparatus. 16. Antenna with part of head. 17. Ventral view showing part of prosternum and its posterior process, partially covered by a tarsus. Scale bars: 0.5 mm (12, 14), 0.05 mm (13, 17), 0.1 mm (15–16).