Bledius hyalinus Bortoluzzi & Caron, 2019

Bortoluzzi, Sidnei & Caron, Edilson, 2019, Bledius hyalinus sp. nov. (Coleoptera: Staphylinidae: Oxytelinae), of the forcipatus group, first recorded from coastal Brazil, Zootaxa 4559 (2), pp. 391-395 : 392-395

Bledius hyalinus Bortoluzzi & Caron , new species

( Figs. 1–12 )

Type Material: Holotype, deposited in DZUP: dissected, male ( Fig. 1, 2 ), with labels: 1) “ BRASIL: Paraná, Pontal / do Paraná, Atami , / 05.iv.2017, E. Caron (col.)”; 2) “ HOLOTYPE / Bledius hyalinus / Bortoluzzi & Caron”.

Paratypes, deposited in DZUP: 2 females, with the same locality label of the holotype .

Additional material: 2 specimens, deposited in DZUP, from the same type locality but collected in VII. 2017; sex undetermined .

Diagnosis: Bledius hyalinus sp. nov., B. actitus and B. playanus have short wings, but B. hyalinus sp. nov. can be distinguished from those species by dark brown body color and translucent elytra; and is lacking projected horn in the supraantennal ridge. B. actitus is brownish black to reddish brown with elytra dark reddish brown in threefifths of its length, while B. playanus is dark reddish brown with elytra pale brownish yellow, both with supraantennal ridge.

Description: Body length: 1.8 mm. Body convex; dorsal surface glossy. Body color dark brown; appendages and meso-metathorax dorsally yellowish. Elytra translucent.

Head: Supraantennal areas well-developed as shelf-like elevation, not anteriorly directed horn ( Fig. 3 ). Frontoclypeal suture present, with anterior margin truncate ( Fig. 3 ); dorsal surface with two long setae. Eyes prominent; ommatidia facets round and strongly convex ( Fig. 3 , 5 ). Antennae, scape longest; antennomere 2 long, about the length of antennomeres 3–5 combined; gradually enlarged toward apex. Labrum with anterior margin sinuous ( Fig. 5 ), without median incision. Epipharynx well-developed ( Fig. 5 ), with on long seta. Mandibles long and bidentate ( Fig. 5 ). Maxillary palpus 4-segmented; segment 3 longest and thickest ( Fig. 6 ). Galea with a few fanlike rows of setae on apex ( Fig. 6 ). Lacinia with few and reduced setae. Labium with long and thin median sclerite ( Fig 6 ); labial palps with second segment shortest; first segment thickest. Mentum large, transverse and trapezoidal ( Fig. 6 ). Gular sutures fused ( Fig. 6 ).

Thorax: Pronotum as long as wide ( Fig. 1 ); shape somewhat pentagonal, gradually narrowing toward the base; with complete internal mid-longitudinal ridge and conspicuous longitudinal median sulcus. Procoxae large and contiguous; protrochantin exposed; procoxal fissure open. Elytra short ( Fig. 1 ); posterior margin truncate, emarginate at elytral suture. Meso and metathoracic underdeveloped ( Fig. 1 ). Shortwinged ( Fig. 1 ). Mesocoxae broad and contiguous. Mesosternum long and thin, reaching at least half-length of mesocoxae. Metasternum not prominent. Tarsal formula 3–3–3.

Abdomen: not parallel-sided, widening posterad to abdominal segments V–VII ( Fig. 7–9 ). Abdominal segments III to VII each with two pairs of paratergites. Abdominal terga II–VII with subbasal transversal carina. Tergum VIII with posterior margin truncate ( Fig. 7 ); sternum VIII with posterior margin projected at the middle ( Fig. 8, 9 ); tergum IX with glandular canal closed dorsally and broadly separated by tergum X ( Fig. 10 ); tergum X shape trapezoidal ( Fig. 10 ).

Male: Aedeagus ( Fig. 12 ) without parameres. Median lobe tubular, larger basally than apically and sclerotized on dorsal and ventral surfaces.

Female: Spermatheca bipartite ( Fig. 11 ); receptacle pot-shaped and heavily sclerotized; spermathecal gland sclerotized, irregularly spherical.

Geographical records: Brazil (Paraná).

Etymology: the specific name “ hyalinus ” is a Latin adjective derivate from Greek (hyalos) that means “of glass or transparent”, an allusion to hyaline elytra, which is possible to see the dorsal plates of pterothorax.

Taxonomical notes: in the forcipatus species group only B. actitus and B. playanus have short wings, and they are known only from the USA. Bledius hyalinus differs from the United States species by the absence of anteriorly directed horn in the supraantennal ridge.

According to the key of United States species of Microbledius (= forcipatus group) of Herman (1972), the most diagnostic features that separete the species are the shape of a horn, eyes size, intraocular width and body color. Thus, we recognized the species as new considering these features, the geographical distribution.

The species, which occur in southern South America are: Bledius albidus . B. albipennis , B. miles, B. minutissimus and B. weiseri , all distributed in Argentina [see fig. 389 in Herman 1986], but none of them were recorded in coastal areas. The unique species recorded from Brazil is B. albidus , which occurs in northern region of Brazil (Amazonas).

Biological Notes: B. hyalinus was collected in March and July of 2017 during field work at the Atlantic beach "Atami", Pontal do Paraná city, state of Paraná; in the ranges 25°36'07.73"S 48°23'20.20"W to 25°35'46.84"S 48°22'43.81"W. It was found in association of Bledius fernandezi (52 adults and 47 larvae), B. bonariensis (1 adult) and Efflagitatus freudei Pacheco, 1973 (Heteroceridae) (6 adults and 12 larvae).

In the field, many specimens of B. fernandezi occurrred in dry sand near shrubby area, while E. freudei occurred in wet sand near streams. However, we do not know if B. hyalinus occurr in dry or wet sand.

Remarks: Bledius species of forcipatus group are restricted to New World with distribution range from central and western parts of North America south to central Argentina.

According to Herman (1986), the species of the group are found in freshwater and saline habits, and may be found in most of the coastal and arid parts of Central and South America. However, with respect to the distribution map of forcipatus group in Central and South America (Fig. 389, p. 211), there are no records of occurrence of the members of the forcipatus group on Brazilian coast. Most of the records in South America are from inland areas.

Thus, the distributional record for Bledius hyalinus represents the first occurrence of the forcipatus group on the coast of Brazil.

Figures

FIGURES 1–4. Bledius hyalinus sp. nov. 1. Habitus, dorsal view (Holotype-DZUP); 2. Labels (Holotype-DZUP); 3. Head, dorsal view; 4. Pronotum, lateral view. Scale bars: Fig. 1 = 1 mm; Figs. 3–4 = 0.125 mm.

FIGURES 5–6. Bledius hyalinus sp. nov. 5. Head, female, dorsal view; 6. Head, female, ventral view. Scale bar = 0.125mm.

FIGURES 7–12. Bledius hyalinus sp. nov. 7. Tergum VIII, male, dorsal view; 8. Sternum VIII, male, ventral view; 9. Sternum VIII (damaged), female, ventral view; 10. Terga IX–X, male, dorsal view; 11. Spermatheca; 12. Aedeagus. Scale bar = 0.125mm.