Malacocis pankararu Araujo & Lopes-Andrade, 2024

Araujo, Lucimar S. & Lopes-Andrade, Cristiano, 2024, Description of the first Brazilian species of the genus Malacocis Gorham (Coleoptera: Ciidae), Zootaxa 5506 (4), pp. 548-554 : 549-552

Malacocis pankararu Araujo & Lopes-Andrade , sp. nov.

Figs 1A–F , 2A–E

Type locality. Riacho Fundo, at Licínio de Almeida , in the state of Bahia, Northeast Region of Brazil (14.6179° S, 42.4725° W) .

Etymology. This species is named in honor of the Pankararu people, the last indigenous community from southwest Bahia, where the species was found.

Diagnosis. Malacocis pankararu sp. nov. is characterized by the antennae with 10 antennomeres, in which the 6th antennomere is wider and more conspicuous than the 5th and 7th ( Figs 1F , 2A , arrows), and by males with very elongated aedeagus ( Fig. 2C ), two tiny anterocephalic tubercles ( Fig. 1A , arrow), a vertexal sex patch ( Fig. 1E , arrow) and a small abdominal sex patch ( Fig. 1D , arrow). Malacocis brevicollis also has antennae with 10 antennomeres, but the 5th and 7th antennomeres are conspicuous; males have a large sex patch, about one-third the length of the first abdominal ventrite at the longitudinal midline, and lack anterocephalic tubercles and vertexal sex patch. Malacocis championi has antennae with 9 antennomeres, in which the 3rd antennomere is as long as the following three antennomeres combined; males lack anterocephalic tubercles or vertexal sex patch, but have a large abdominal sex patch, similar to that of males of M. brevicollis .

Description, male holotype ( Fig. 1A–C ). Adult fully pigmented, dark brownish. Measurements in mm: TL 1.19, PL 0.41, PW 0.50, EL 0.78, EW 0.64, GD 0.53. Ratios: PL/PW 0.82, EL/EW 1.22, EL/PL 1.91, GD/EW 0.83, TL/EW 1.86. Body convex, dorsum and venter dark brown; antennae (except for club), palpi and tarsi yellowish brown; vestiture consisting of yellowish, suberect, stout bristles; ventral vestiture of yellowish decumbent setae, most conspicuous on abdominal ventrites. Head not visible from above, except for anteriormost portion; concave at vertex; dorsal punctures shallow, sparse, with markedly reticulate interspaces; dorsal bristles 0.02–0.03 mm long; anterocephalic edge sinuous, with two tiny teeth ( Fig. 1A , arrows); vertex with one setose patch at middle ( Fig. 1E , arrow). Gula one-fourth as wide as head. Antennae ( Figs 1F , 2A ) with ten antennomeres, as follows (in mm, left antenna measured): 0.05, 0.04, 0.03, 0.02, 0.01, 0.02, 0.01, 0.04, 0.04, 0.06 (FL = 0.09, CL = 0.14, CL/FL = 1.56). Eyes oval, coarsely faceted; each bearing about 80 ommatidia; GW = 0.11mm. Pronotum with moderately deep, single coarse punctation; punctures separated by one to two-punctures widths; interspaces, markedly reticulate; anterior angles broadly rounded, not produced forward; bristles 0.01–0.03 mm long on disc (not fitting in distinct size classes), and 0.04 mm long on the anterior border; anterior edge smooth, broadly round; lateral carinae barely crenulate, not explanate, not visible when seen from above. Scutellar shield subtriangular, bearing few punctures and decumbent bristles; BW 0.15. Elytra punctation confuse (non-seriate), single, coarser, and deeper than that of pronotum; interspaces, irregular, shiny; vestiture confuse, similar to those of pronotum, but comparatively denser; bristles variable in size, 0.02–0.05 mm long on disc (not fitting in distinct size classes). Hind wings developed, apparently functional. Hypomera with sparse, shallow punctation; interspaces, microreticulate. Prosternum in front of coxae strap-like, subglabrous; interspaces, microreticulate. Prosternal process parallel-sided, 2.7x as long as wide; apex rounded. Protibiae ( Fig. 2B ) with maximum width (at apex) about one-third its length; apical edge with a row of spines; outer apical angle projected as a tooth ( Fig. 2B , arrow). Meso- and metatibiae ( Fig. 2B ) about 4.8x as long as wide; apex with a row of spines; outer apical angle rounded and devoid of spines. Metaventrite about 1.4x as long as the first abdominal ventrite; punctures sparse, shallow; interspaces, microreticulate; discrimen about one-fourth as long as the metaventrite. Abdominal ventrites with moderately deep, coarse punctures, separated from each other by one puncture-width or less, each bearing one yellowish, decumbent seta; interspaces, microreticulate; length of ventrites (in mm, from base to apex at the longitudinal midline) as follows: 0.16, 0.06, 0.06, 0.06, 0.08; first abdominal ventrite bearing one margined, circular sex patch ( Fig. 1D , arrow) located posterad of center, with a tuft of long setae and a transverse diameter of 0.04 mm. Male abdominal terminalia in a paratype ( Fig. 2C ) with sternite VIII with posterior margin slightly sinuous and bearing long setae at corners; anterior portion broadly emarginate at middle. Tegmen robust, about 2.7x as long as wide, sides straight and parallel-sided when seen from above or below, but conspicuously bent at middle in lateral or oblique view. Basal piece triangular. Penis subparallel-sided in dorsal or ventral view, arched in lateral view, about half as long as tegmen, and about 6.5x as long as wide; apex spatula-shaped, membranous.

Females. Anterocephalic edge without tubercles and vertexal sex patch, and first abdominal ventrite without sex patch. Gula similar in size to that of males, but lateral edges comparatively less arched. Female abdominal terminalia ( Fig. 2E ) as follows: ovipositor short, with paraprocts 0.43x as long as gonocoxites combined; baculi of paraprocts broadly arched, their tips fused to the tips of the respective proctigeral baculi; apex of proctiger laying close to the apices of gonocoxites; gonocoxites transversally divided into two lobes ventrally; gonostyli short, 1.6x times as long as wide.

Type series. Holotype m# ( CELC): “ BR: BA Licínio de Almeida Riacho Fundo 21.xii.2008 leg. L. S. Araujo \ Malacocis pankararu Araujo & Lopes-Andrade HOLOTYPUS [printed in red paper]” . Paratypes: 116 specimens (96 CELC, 10 CERPE), same data as the holotype. All paratypes are additionally labelled “ Malacocis pankararu Araujo & Lopes-Andrade PARATYPUS [printed in yellow paper]” .

Measurements (in mm). Males (n=10, including the holotype): TL 1.10–1.32 (1.21 ± 0.06), PL 0.41–0.48 (0.44 ± 0.03), PW 0.46–0.59 (0.54 ± 0.04), EL 0.69–0.87 (0.77 ± 0.05), EW 0.59–0.68 (0.64 ± 0.03), GD 0.52–0.59 (0.54 ± 0.02), PL/PW 0.76–0.88 (0.82 ± 0.04), EL/EW 1.08–1.32 (1.21 ± 0.06), EL/PL 1.54–1.96 (1.76 ± 0.14), GD/EW 0.83–0.89 (0.85 ± 0.02), TL/EW 1.78–2.00 (1.90 ± 0.06). Females (n=10): TL 1.16–1.39 (1.26 ± 0.08), PL 0.39–0.53 (0.47 ± 0.04), PW 0.48–0.60 (0.55 ± 0.04), EL 0.73–0.89 (0.79 ± 0.05), EW 0.59–0.71 (0.65 ± 0.04), GD 0.52–0.62 (0.57 ± 0.04), PL/PW 0.78–0.90 (0.84 ± 0.05), EL/EW 1.13–1.30 (1.21 ± 0.07), EL/PL 1.50–1.95 (1.71 ± 0.15), GD/EW 0.81–0.95 (0.86 ± 0.04), TL/EW 1.81–2.00 (1.92 ± 0.07).

Host fungus. All individuals of M. pankararu were collected and bred in basidiomes of Trametes hydnoides (Sw.) Fr., 1838 ( Polyporales : Polyporaceae ). It is a common wood-rotting fungus in tropical and subtropical America, occurring from north Florida to south Argentina ( Roberts & Evans, 2011), and is commonly found in both natural and urbanized open areas in Brazil (pers. obs.).

Distribution. Malacocis pankararu is known only from the type locality in the Caatinga biome, close to the transition to the Atlantic Forest biome. The Caatinga is an open area under scarce rain, with soil almost fully exposed to sunlight, leading to severe dry conditions. The vegetation is formed by plants adapted for reducing water loss. The basidiomes were collected in a rotten-wood next to a stream and then were kept in the laboratory to let beetles develop, without any further substrate.

Comments. COI sequences of two males of M. pankararu sp. nov. are available in GenBank (HQ986909.1, HQ986910.1). These sequences were included in the phylogenetic analysis performed by Lopes-Andrade & Grebennikov (2015). The species cited as “ Malacocis sp. A ” by Araujo et al. (2015) is a distinct species, known only from a single male specimen. It was collected at the Reserva Biológica de Sooretama, within the Atlantic Forest biome in the state of Espírito Santo, Southeast Region of Brazil. We prefer to wait for more specimens to be collected to adequately describe that species.

Figures

FIGURE 1. Malacocis pankararu sp. nov., male holotype (A–C) and male individual under SEM (D–F) from the type locality Licínio de Almeida (Bahia, Brazil). A. Dorsal view, with pointing to the anterocephalic tubercles. B. Lateral view. C. Ventral view. D. Ventral view, with an arrow pointing to the abdominal sex patch. E. Dorsal view of head and anterior portion of pronotum, showing the vertexal sex patch (arrow). F. Part of head and pronotum, showing the 6th antennomere wider than the 5th and 7th (arrow). Scale bars: 0.5 mm (A–D), 0.1 mm (E–F).

FIGURE 2. Malacocis pankararu sp. nov., dissected parts of a male (A–C) and a female (E), and undissected female paratype (D) from the type locality Licínio de Almeida (Bahia, Brazil). A. Left antenna, with an arrow pointing to the wide 6th antennomere. B. From left to right, parts of the left fore, meso and hind legs, with an arrow pointing to the outer apical tooth of protibia. C. Parts of male abdominal terminalia showing the VIII-sternite (viii-st), basal piece (b.p), tegmen (teg) in lateral view and penis (pen) in lateral view. D. Dorsal view. E. Parts of female abdominal terminalia, showing the spiculum ventrale (s.v), paraprocts (pp), proctiger (pt), gonocoxites (gc) and gonostyli (gs). Scale bars: 0.1 mm (A–C, E), 0.5 mm (D).