Ceracis tzotzilicus, Souza-Gonçalves & Lopes-Andrade, 2020

Souza-Gonçalves, Igor & Lopes-Andrade, Cristiano, 2020, Ceracis tzotzilicus sp. nov. (Coleoptera: Tenebrionoidea: Ciidae) from Guatemala and Mexico, Zootaxa 4780 (2), pp. 379-386 : 380-385

Ceracis tzotzilicus sp. nov.

Figs 1–22

urn:lsid:zoobank.org:pub:BDA42D7F-AEC0-4F5F-895B-1D3F46FBC728

Type locality. San Cristóbal de las Casas, coordinates 16º44’N 92º38’W (Chiapas, Mexico) .

Type material. Holotype: ♂ ( CNC) “ MEX., HIS., 3 mi. N. S. Cristobal de las Casas 12.VI.1969 E.E. Lindquist \ Bracket fungi \ Ceracis tzotzilicus Souza-Gonçalves & Lopes-Andrade HOLOTYPUS [red paper]” . Paratypes: 121 ♂♂ and 78 ♀♀ as follows: 105 ♂♂ (35 CELC, four dissected; 3 CMN; 67 CNC) and 69 ♀♀ (22 CELC, two dissected; 1 CMN; 46 CNC) same data as the holotype ; 2 ♂♂ (1 CMN; 1 CNC) “ MEX., HIS., 3 mi. N. S. Cristobal de las Casas 12.VI.1969 E.E. Lindquist \ Bracket fungi \ Ceracis sp. Det. J.F. Lawrence ” ; 15 ♂♂ (8 CELC, one dissected; 7 FMNH) and 9 ♀♀ (5 CELC; 4 FMNH) “ Finca Monserat , W. slope Volcan Acatenango, Município Yepocapa, Chimaltenango, V:17:1948 GUAT. R.D. Mitchell leg. 214.7100 ft., ex dry polypore fungus \ CHICAGO

NAT. HIST. MuSEUM [sic], Guatemala Zool. Exped. (1948)”. All paratypes additionally labeled “ Ceracis tzotzilicus Souza-Gonçalves & Lopes-Andrade PARATYPUS [yellow paper]” .

Diagnosis. Ceracis tzotzilicus sp. nov. can be distinguished from other species in the genus by the following characteristics: Antennae 9-segmented ( Fig. 5 ). Males with anterocephalic edge produced and elevated forming a wide lamina, which is broadly emarginate apically ( Figs 1, 3 ), and pronotum deeply emarginate forming two triangular plates ( Figs 1, 3, 4 ). C eracis tzotzilicus sp. nov. resembles Ceracis bicornis (Mellié) in the fine and sparse pronotal punctation, but in the latter species the male anterocephalic lamina is straight at apex and female ovipositor has conspicuous gonostyli.

Description, male holotype ( Figs 1–4 ). Adult, fully pigmented and in good condition, but lacking the left antenna. Measurements in mm: TL 1.67, PL 0.64, PW 0.67, EL 1.04, EW 0.72, GD 0.67. Ratios: PL/PW 0.95, EL/ EW 1.44, EL/PL 1.63, GD/EW 0.93, TL/EW 2.33. Body elongate, convex; dorsum and venter reddish dark brown; antennae yellowish brown, club dark brown; palpi and tarsi yellowish brown; dorsal vestiture single, consisting in minute suberect setae, barely visible at high magnifications (>50x); ventral vestiture of fine decumbent setae easily discernible at high magnifications (>50x). Head with the anteriormost portion visible from above; dorsum concave, with a conspicuous, short protuberance on vertexal disc; punctures fine, shallow, separated from each other by two punctures-widths or less; surface glabrous; interspaces, finely microreticulate; anterocephalic edge produced and elevated, forming a wide lamina with broadly emarginate apex. Antennae ( Fig. 5 , left antenna from paratype) 9- segmented, lengths as follows (in mm, right antenna measured): 0.08, 0.04, 0.03, 0.02, 0.02, 0.01, 0.05, 0.06, 0.07 (FL 0.08 mm, CL 0.17 mm, CL/FL 2.04). Eyes coarsely facetted; each bearing about 90 ommatidia; GW 0.16 mm. Maxillae ( Fig. 8 , right maxilla in paratype) with distinctly articulated galea; lacinia more or less fused to stipes; apical maxillary palpomere pyriform, 1.5X as long as wide, widest near base and narrowly rounded at apex. Mandibles ( Fig. 6 , from paratype) as long as wide. Labium ( Fig. 7 , from paratype) with rounded contour of apical portion of prementum in lateral view; labial palpi each with three palpomeres. Gula 0.32x as wide as head. Pronotum ( Fig. 4 ) finely, shallowly punctate; punctures of one size, with the exception of median impunctate line beginning around eight puncture-widths of base until disc; punctures scattered, separated from each other by 2–3 puncture-widths; interspaces microreticulate and shiny; vestiture single, consisting of minute, pale yellowish setae (<0.01 mm); anterior pronotal edge deeply emarginate forming two short triangular plates, slightly divergent and with acute apex; lateral edges not crenulate, not explanate and not visible when seen from above. Scutellar shield triangular, bearing few punctures and few minute setae; BW 0.10 mm, SL 0.07 mm. Elytra with non-seriate, dual punctation; megapunctures finer and closer than those on pronotum, shallow, about twice as large as micropunctures, separated from each other by 1–2 megapuncture-widths; interspaces, smooth and shiny; vestiture single, consisting of minute pale yellowish setae (~ 0.01 mm) arising from megapunctures. Metathoracic wings developed, apparently functional. Hypomera with fine, shallow punctation; each puncture bearing one fine decumbent seta; interspaces microreticulate. Prosternum in front of coxae concave; interspaces, microreticulate. Prosternal process laminate, as long as prosternum at midline; acute at the apex. Protibiae ( Fig. 9 , left protibia from paratype) with maximum width of about one-fourth of its length, expanded at apex. Meso- and metatibiae ( Figs 10–11 , left meso- and metatibia from paratype) each with spines in apical edge. Metaventrite with fine, shallow punctures; interspaces, microreticulate; discrimen indiscernible. Abdominal ventrites with fine, shallow punctures, separated from each other by one puncture-width or less, each bearing one fine decumbent pale yellowish seta; interspaces, microreticulate; length of ventrites (in mm, from base to apex at the longitudinal midline) as follows: 0.25, 0.08, 0.06, 0.07, 0.10; first abdominal ventrite with large circular, setose sex patch posteriorly, not margined, transverse diameter of 0.08 mm. Male terminalia (from paratype) ( Figs 12–15 ): Sternite VIII ( Fig. 12 ) with posterior margin slightly emarginate medially; corners broadly rounded, bearing long and short setae; lateral margins diverging; anterior margin biconcave, sub-rounded, heavily sclerotized medially forming short strut ( Fig. 12 , big black arrow). Tegmen ( Fig. 14 ) 2X as long as wide, widest near apex, apical portion deeply and broadly emarginate; lateral edges angulate near apex; outer apical edge broadly rounded. Basal piece ( Fig. 13 ) subtriangular, 1.4X as long as wide. Penis ( Fig. 15 ) elongate, 0.8X as long as tegmen, 4.9X as long as wide; lateral edges sclerotized forming two struts converging near apex; lateral edges slightly angulate near apex ( Fig. 15 , small black arrows); apex rounded.

Females ( Figs 16–18 ). Anterocephalic edge anteriorly truncate, barely convex; vertex convex. Anterior pronotal edge rounded. Otherwise like males, but devoid of head and pronotal ornamentations, and abdominal sex patch. Female terminalia ( Figs 17–18 ) with spiculum ventrale ( Fig. 17 ) 1.7X as long as gonocoxites; ovipositor ( Fig. 18 , distorted after compression between slide and cover slip) presenting reduced paraprocts, shorter than gonocoxites and barely discernible; each baculus of paraprocts bowed and completely fused to respective proctigeral baculus ( Fig. 18 ); gonocoxites without ventral lobes and gonostyli.

Variation. Males, measurements in mm (n= 11, including the holotype): TL 1.58–1.78 (1.67 ± 0.07), PL 0.55– 0.68 (0.62 ± 0.04), PW 0.63–0.70 (0.67 ± 0.02), EL 0.95–1.18 (1.05 ± 0.07), EW 0.65–0.75 (0.71 ± 0.03), GD 0.63–0.70 (0.65 ± 0.04), PL/PW 0.85–1.00 (0.93 ± 0.05), EL/EW 1.36–1.59 (1.48 ± 0.07), EL/PL 1.41–1.96 (1.70 ± 0.18), GD/EW 0.88–0.93 (0.91 ± 0.02), TL/EW 2.23–2.43 (2.36 ± 0.06). In some males, the pronotal plates are short ( Fig. 19 ) or the plate of head is short and pronotal edge is rounded ( Figs 20–21 ). Females, measurements in mm (n= 10): TL 1.45–1.73 (1.63 ± 0.08), PL 0.53–0.63 (0.58 ± 0.06), PW 0.55–0.70 (0.64 ± 0.05), EL 1.00–1.10 (1.05 ± 0.04), EW 0.63–0.78 (0.70 ± 0.05), GD 0.58–0.70 (0.65 ± 0.04), PL/PW 0.82–1.00 (0.91 ± 0.05), EL/EW 1.37–1.68 (1.50 ± 0.10), EL/PL 1.64–2.22 (1.82 ± 0.17), GD/EW 0.83–0.97 (0.93 ± 0.05), TL/EW 2.13–2.52 (2.32 ± 0.11). In both males and females, coloration can range from reddish brown to reddish dark brown. In specimens from Guatemala the pronotal punctation is slightly sparser than in the Mexican specimens.

Host fungi. Unknown.

Etymology. The species epithet is a combination of the terms “tzotzil” and the Greek noun “ikos” (=belonging to), both in the genitive singular. The name is a reference to the Tzotzil, an indigenous Maya people from the central Chiapas highlands in southern Mexico, which is also the native name of the type locality.

Distribution. Ceracis tzotzilicus was collected in two localities over 2000 m above sea level: Central Highlands region of Chiapas ( Mexico) dominated by Coniferous Forest vegetation, and in the stratovolcano Acatenango close to Antigua ( Guatemala) ( Fig. 22 ).

Comments. Currently, four species-groups are recognized within Ceracis (number of species between parentheses): the cucullatus (10), furcatus (4), furcifer (4) and singularis species-groups (3). This arrangement leaves 32 species (including Cer. tzotzilicus ) without species-group assignment within the genus. The cucullatus- group was revised by Antunes-Carvalho & Lopes-Andrade (2011, 2013), with four new species from Australia added by Lawrence (2016). Within the cucullatus -group, Cer. bicornis (Mellié) is the unique species that was not redescribed yet and may be a species complex. The furcatus- group was established by Lopes-Andrade (2002) and may include possible synonyms ( Lawrence 1967); it is in urge of a taxonomic revision. The furcifer- group was recently revised by Pecci-Maddalena & Lopes-Andrade (2017). The singularis group was established by Lopes-Andrade et al. (2002) and its species seem to be well defined. Although Cer. tzotzilicus resembles Cer. bicornis (see Diagnosis), we prefer not to assign it to either the cucullatus or any other species-group within Ceracis . We are currently conducting a phylogenetic analysis and major taxonomic propositions will be provided in forthcoming works.

Figures

FIGURE 22. Known geographic distribution of Ceracis tzotzilicus sp. nov. in Guatemala and Mexico.

FIGURES 1–8. Ceracis tzotzilicus sp. nov., male holotype (1–4), antenna and mouth parts from the type locality San Cristóbal de las Casas (Mexico: Chiapas) (5–8): 1. Dorsal view. 2. Lateral view. 3. Ventral view. 4. Scutellar shield and part of pronotum and elytra. 5. Left antenna. 6. Mandible. 7. Labium. 8. Right maxilla. Scale bars: 0.5 mm (1–3); 0.2 mm (4); 0.1 mm (5) 0.05 mm (6–8).

FIGURES 9–15. Ceracis tzotzilicus sp. nov., tibiae and aedeagus of paratype from the type locality San Cristóbal de las Casas (Mexico: Chiapas) (9–15): 9. Left protibia. 10. Left mesotibia. 11. Left metatibia. 12. Sternite VIII. 13. Basal piece. 14. Tegmen. 15. Penis. Scale bars: 0.1 mm (9–11) 0.05 mm (12–15).

FIGURES 16–18. Ceracis tzotzilicus sp. nov., dorsal view of a female (16) and terminalia of a paratype from the type locality San Cristóbal de las Casas (Mexico: Chiapas) (17–18): 16. Dorsal view. 17. Sternite VIII with spiculum ventrale (sv). 18. Oviposi¬tor, showing gonocoxites (gc) and proctiger plus paraprocts (pt + pp). Scale bars: 0.5 mm (16); 0.05 mm (17–18).

FIGURES 19–21. Male variation of Ceracis tzotzilicus sp. nov. as observed in paratypes from the type locality San Cristóbal de las Casas (Mexico: Chiapas). Scale bar: 0.5 mm (19–21).