Microlinus perobanus Busanello and Caron, 2016

Busanello, Dilson G. C. & Caron, Edilson, 2016, First Record and a New Species of the Rare Xantholinini GenusMicrolinusCasey (Coleoptera: Staphylinidae: Staphylininae) in Brazil, The Coleopterists Bulletin 70 (3), pp. 606-610 : 606-610

Microlinus perobanus Busanello and Caron , new species

( Figs. 1–15 )

Material Examined. Holotype. Male, dissected, deposited in DZUP, labels: 1) “BRA[ Brazil], Paraná,

606

0.5 mm.

Tuneiras do Oeste,/Reserva Biológica das Perobas/ 3.8 S23°50′39″; W52°44′43.26″;/ 534m / 18-IX- 2015 /D.G.C. Busanello & E. Caron, col.” [white label, printed in black]; 2) “ Holotype / Microlinus perobanus /Busanello & Caron, 2016 designated by Busanello & Caron, 2016” [red label, printed in black]. Three paratypes: one male, dissected, deposited in DZUP, the same data as for holotype; 2) “ Paratype / Microlinus perobanus /Busanello & Caron, 2016” [yellow label, printed in black]; one male deposited in FMNH and one female deposited in DZUP, labels: 1) “BRA[ Brazil], Paraná, Tuneiras do Oeste ,/Reserva Biológica das Perobas/ 3.20 S23°50′39″; W52°44′43.26″;/ 534m / 18-IX-2015 / D.G.C. Busanello & E. Caron, col.” [white label, printed in black]; 2) “ Paratype / Microlinus perobanus / Busanello & Caron, 2016” [yellow label, printed in black] .

Diagnosis. Microlinus perobanus differs from M. pusio by having the head and abdomen darker than the rest of the body, the labrum truncate on the anterior margin, and the apex of the median lobe of the aedeagus clearly tapered and pointed.

Description. Male. Maximum body length 2.5 mm, maximum elytral width 0.4 mm. Body elongate and parallel-sided ( Fig. 1 ); brownish with head and abdomen darker and appendices lighter. Body glossy; head with minute, sparse setigerous punctation, gradually disappearing towards midline; pronotum with dorsal and lateral rows of setigerous punctures; elytral and abdominal setigerous punctation fine, sparse, gradually disappearing towards midline on abdomen. Head: Longer than wide, slightly widened posteriorly; eyes small and not prominent, tempora longer than length of eyes. Antenna distinctly geniculate and short ( Fig. 2 ); antennomeres III–XI with dense, fine pubescence; scape and pedicel longer than wide, scape longest, almost as long as 5 following antennomeres combined; antennomeres III–X conspicuously wider than long, gradually increasing in width towards apex; antennomere XI longer than wide, almost as long as 2 preceding antennomeres combined. Labrum short, slightly transverse ( Fig. 3 ); anterior margin truncate; lateral angles sinuous; long apical setae. Mandibles almost symmetric, with 2 internal teeth ( Fig. 4 ). Maxilla with galea extending beyond apex of lacinia ( Fig. 5 ); palpomere I as long as wide and shortest; palpomere II as long as wide, conspicuously widened at apex; palpomere III 2 times wider than long, slightly narrowing toward apex; palpomere IV thin and about half length of palpomere III. Labium with palpomere II longer than III, widest at median third ( Fig. 6 ); palpomere III thin, parallel-sided. Gular sutures fused at basal half. Thorax: Pronotum 1.5 times longer than wide; apical fourth with sides converging to anterior margin and basal 3/4 somewhat parallel-sided; anterior margin emarginated. Prosternum slightly elevated medially, with a short, triangular process. Elytra slightly longer and wider than pronotum; metathoracic wings developed; mesocoxae separated from each other by distance about half width of each mesocoxa, mesoventrite process broad and somewhat pointed at the apex. Tarsal formula 5-5-5; protibia with internal emargination on apical third ( Fig. 7 , black seta); protarsus with first 4 tarsomeres strongly dilated ( Fig. 7 ); metatibia with apical ctenidium. Abdomen: Segments III–VII parallel-sided; tergite VIII with posterior margin slightly projected on median third ( Fig. 8 ); sternite VIII with posterior margin rounded ( Fig. 9 ); tergite IX without ventral struts ( Fig. 10 ); sternite IX 2 times longer than wide, base rounded, apex barely sclerotized with set of setae somewhat resembling a crown ( Fig. 11 ); tergite X 2 times longer than wide, apex barely sclerotized with set of setae somewhat resembling a crown ( Fig. 10 ). Aedeagus elongate, median lobe almost 3 times longer than parameres ( Fig. 12 ); median lobe tapered and pointed at apex, lateral lobes slightly exceeding apex of median lobe.

Female. Similar to male, except first 4 protarsomeres less dilated; tergite VIII with posterior margin truncate ( Fig. 13 ); tergite IX in a single plate, lateral hemitergites completely fused ( Fig. 14 ); sternite IX with anterior margin clearly emarginated ( Fig. 15 ); tergite X short ( Fig. 14 , anterior margin indicated as dashed line).

Geographical Records. The species is known only from the type locality in southern Brazil (Paraná) .

Etymology. The specific name refers to the Brazilian natural reserve in the Atlantic Forest where the type material was collected, in Portuguese “Reserva Biológica das Perobas”, which the singular noun “Peroba” added to the Latin suffix masculine “–anus” that means pertaining to.

Biological Notes. The specimens of M. perobanus were collected from sifted leaf litter on typical paleo-argillic brown soil (paleudalf) and extracted using the Winkler technique.

Figures

Fig. 1. Microlinus perobanus, holotype. Scale bar =

Figs. 2–9. Microlinus perobanus, male. 2) Antenna; 3) Labrum, dorsal view; 4) Mandibles, dorsal view; 5) Maxilla, dorsal view; 6) Labium, ventral view; 7) Protibia and protarsus, external view; 8) Tergite VIII, dorsal view; 9) Sternite VIII, ventral view. Scale bars = 2) 0.5 mm; 3) 0.125 mm; 4–9) 0.25 mm.

Figs. 10–15. Microlinus perobanus. 10) Male tergites IX and X, dorsal view; 11) Male sternite IX, ventral view; 12) Aedeagus, ventral view; 13) Female tergite VIII, dorsal view; 14) Female tergites IX and X, dorsal view, anterior margin of tergite X with dashed line; 15) Female sternite IX, ventral view. All scale bars = 0.25 mm, except 12) 0.5 mm.