Austrolimnius cleidecostae, Polizei & Costa & Bispo, 2020

Polizei, Thiago Tadeu Silva, Costa, Lucas de Souza Machado & Bispo, Pitágoras da Conceição, 2020, Austrolimnius cleidecostae, a new species of riffle beetle (Coleoptera: Elmidae) from Brazil with habitat notes and updated key of the Brazilian species of the genus, Papéis Avulsos de Zoologia (Pap. Avulsos Zool., S. Paulo) 60 (12), pp. 1-10 : 2-5

Austrolimnius cleidecostae sp. nov.

( Figs. 1-24 )

Type Material: Holotype male ( MZSP): “ ♂ // Holo- / type // BRASIL.SãoPaulo.SãoMiguel/Arcanjo.ParqueEstadual Carlos / Botelho. 795 m asl. 16.VII.2013 / 24°08′30,0″S 47°59′41,8″W / Polizei, T. T.S. & Costa, L.S.M. leg. // MZSP 31185 // ( MZSP)” . Paratypes (20 specimens): same locality data as holotype (1♂, 1♀, MZSP 31186-31187 ; 1♂, 1♀, USNM; 1♂, 1♀, BMNH). “ BRASIL. São Paulo. Cunha / Parque Estadual Serra do Mar / 988 m asl. 23°16′28,4″S 45°02′01,6″W / 25.VII.2012 Polizei & Costa leg. ” (1♂, 2♀, MZSP 31188-31190 ; 1♀, BMNH). “ BRASIL. Santa Catarina. Rancho / Queimado. Riacho das Antas. / 791 m asl. 27°41′35,0″S 49°00′38,0″W / 01.X.2016. Polizei, T. T.S. leg. ” (4♂, 3♀, MZSP 31194-31196 , 31252-31255 ), [in alcohol 96%]. “ BRASIL. Santa Catarina. São / Bonifácio. Riacho Dona Bebê. / 470 m asl. 27°54′32,0″S 48°54′47,8″W / 29.IX.2016. Polizei, T. T.S. leg. ”(2♂, 1♀, MZSP 31191-31193 ) [in alcohol 96%] .

Diagnosis: Body subparallel; cuticle alutaceous; general colour dark-brown, with light-yellow antennae, mouthparts, legs and abdominal ventrite V. Mandibles with an articulated sclerotized process on inner subapical edge. Pronotum with surface alutaceous and without setae, inconspicuously micropunctated, and with longitudinal median impression on basal ⅔ of disc. Epipleura covered by tomentum, each one with two rows of granules. Mesotarsus with a pair of long and thin setae on each tarsomere. Aedeagus with phallobase approximately 3× as long as wide; parameres reaching ⅘ of penis length, with apex rounded with tuft of long setae and rows of micro punctures; penis slightly narrowed at apex with sensorial pores; basolateral apophyses with two lobes; fibula absent; corona present, subquadrate. Female genitalia with valvifer membranous, curved and convergent at base; coxites narrowed apicad; styli slightly curved and with base divergent, apical portion rounded and micropunctated.

Description: Male: Body subparallel; cuticle alutaceous; general colour dark-brown, antennae, mouthparts, legs and ventrite V light-yellow. Body size range (n = 5): total length 1.18-1.20 mm; greatest width 0.45-0.50 mm.

Head: Partially retracted; without impressions, surface micropuntated. Eyes protruding laterally ( Figs. 1-3 ). Antennae filiform with 11 antennomeres, with few short and thin setae on apex of each antennomere. Clypeus elongate and convex, surface alutaceous without punctures or setae. Frontoclypeal suture straight. Labrum ( Fig. 4 ) subrectangular, anterior margin rounded and slightly prominent at middle; surface with long and thin setae restrict to latero-posterior region (represented by punctures); disc without setae or punctures; antero-lateral margin with long curly setae; antero-posterior margin arcuate. Mandible ( Figs. 7-8 ) asymmetrical, subtriangular, with an articulated sclerotized process on inner subapical edge, with apex rounded in left and tapered in right mandible; lateral lobe more pronounced in dorsal view ( Figs. 7 A-B); prostheca membranous forming a long lobe below articulated sclerotized process, with long setae on apex and short dense setae on the lateral margin; ventrally, mandible with a latero ventral stout seta; molar region with several transversal carinae ( Figs. 8 A-B). Maxilla ( Fig. 5 ): cardo elongate, margins sinuous, with one stout seta; stipes large and divided; palpi with four palpomeres; a sensorial pore on each palpomere; distal palpomere elongate, with one seta near middle and several sensilla at apex; galea elongate with one seta near middle and four wide short setae on apex; lacinia subrectangular, 2× as long as wide, and with a marginal fringe of long setae. Labium ( Fig. 6 ): palpi with three palpomeres, without setae or pore; palpomeres 1-2 transverse; apical palpomere of approximately the length of the basal two combined; ligula wider than long, anteri- or margin prominent on middle, antero-lateral angles rounded. Epipharynx membranous, anterior margin concave, with a row of robust setae, and with latero-dorsal angles with three short spines. Gena densely covered by tomentum.

Thorax: Pronotum approximately as long as wide ( Figs. 1, 3 , 9 ); anterior margin moderately arcuate; an- terior angles slightly protruding; lateral margins moderately sinuous; posterior angles acute; posterior margin emarginated, strongly on middle, and smooth near the posterior angles. Pronotum surface alutaceous, glabrous, with inconspicuous micropunctures ( Fig. 9 ); sublateral carinae complete, sinuous, reaching anterior and posterior margins ( Figs. 1 , 9 ); longitudinal median impression on posterior ⅔ ( Figs. 1 , 9 ). Elytra ( Figs. 1, 3 ) 1.5× longer than wide; anterior margin arcuate; lateral margins slightly arcuate; apex rounded; median suture slightly elevated; a pair of sublateral carinae extending to apex; surface alutaceous with inconspicuous rows of punctures; lateral margin with row of long and thin setae ( Fig. 3 ). Scutellum oval. Epipleura covered with tomentum with two rows of granules ( Fig. 3 ). Hind wings absent. Prosternum broad, as long as wide, with lateral portion covered by tomentum; disc alutaceous ( Fig. 2 ); prosternal process wide, V-shaped, surpassing procoxae, with a carina on disc, and towards the anterior margin of prosternum ( Fig. 2 ). Hypomerum 3× as long as wide, covered by tomentum. Mesoventrite as long as wide, with a weak cavity to receive prosternal process. Metaventrite as long as wide, covered laterally by tomentum; disc alutaceous with a complete longitudinal line and a lateral carina; surface with inconspicuous punctures. Legs covered with tomentum, except tibiae and tarsi. Coxae rounded. Trochanter as long as wide, with a row of short and stout setae ( Fig. 2 ). Femora robust, 3× longer than wide; pro and mesofemur with a dense row of setae on lateral margin.Tibiae narrow, 6× longer than wide, with a complete row of spines on protibia; meso and metatibiae with two rows of spines reaching ⅔ of the length, and with a row of golden setae between the row of spines. Tarsus elongated; apical tarsomere as long as four pre- ceding combined; pro- and metatarsi with a pair of stout and short setae on each tarsomere; mesotarsus with a pair of long and thin setae on each tarsomeres. Claws large and stout.

Abdomen: Five ventrites ( Figs. 2-3 , 10 ) with margins moderately arcuate; discal surface alutaceous and covered laterally by tomentum. First ventrite with a pair of longitudinal median carinae, extending from anterior to posterior margins, without tomentum. Fifth ventrite with a shallow transverse depression on anterior third; one pair of spiracles antero-laterally; apex slightly sharpened with few setae dorso-laterally and punctures on apex ( Fig. 10 ). Tergite VIII ( Fig. 11 ) almost as long as wide, posterior margin prominent and widely rounded; surface with inconspicuous punctures, apex with a row of short setae. Sternite VIII ( Fig. 13 ) triangular; anterior margin emarginated concave, posterior margin moderately sharp; surface with setae on disc and antero-laterally; apex with a row of punctures; integument with short scale-like setae.Spicule subrectangular and bifurcated at the apical third; apical margin with punctures ( Fig. 18 ).

Aedeagus: ( Figs. 16-17 ). Phallobase approximately 3× as long as wide; in lateral view ( Fig. 16 ), wider at apex. Parameres reaching ⅘ of penis length, slightly narrowed to apex, surface with punctures; apex rounded with fringe of long setae and rows of micro punctures ( Figs. 16-17 ). Penis approximately as long as phallobase, 4× as long as wide; slightly narrowed at apex with sensorial pores; in lateral view ( Fig. 16 ), dorsal margin sclerotized, ventral margin membranous; basolateral apophyses with two lobes; fibula absent; corona present, subquadrate ( Fig. 17 ).

Female: External morphology similar to male, except the pattern of setae on mesotarsus. All tarsi have a pair of stout and short setae on each tarsomere. The golden row of setae between the row of spines in the meso and metatibiae are absent. Tergite VIII has the basal margin emarginated, and apex arcuate; surface with punctures and tuft of long setae on apex ( Fig. 12 ). Sternite VIII elongate; basal margin widely rounded and prominent at middle; apex with setae and punctures; surface with short setae on the disc and antero-laterally; basal projection 3× longer than sternite, curved ( Fig. 14 ); integument similar to that of the male ( Fig. 15 ).

Female genitalia ( Fig. 19 ): Ovipositor symmetrical. Valvifer membranous, moderately smaller than coxites; curved and convergent on base; wider at apex than at base; apex with punctures; baculus sclerotized. Coxites wider at base than apex, narrowed at the apex, divided by a transverse line; surface with micropunctures, without setae. Styli slightly curved and divergent; apical portion rounded and covered with micropunctures.

Etymology: the specific epithet cleidecostae is a tribute to Dr. Cleide Costa in honour of her many contributions to the study of Coleoptera .

Type locality: São Miguel Arcanjo, São Paulo state, Brazil.

Distribution: São Paulo and Santa Catarina states, Brazil.

Figures

Figures 1-3. Austrolimnius cleidecostae sp. nov. Habitus of holotype (Male). (1) Dorsal view;(2) Ventral view;(3) Lateral view.Scale bars:0.5 mm.

Figures 4-6. Austrolimnius cleidecostae sp. nov., mouthparts, dorsal view. (4) Labrum (setae are represented by punctures); (5) Right maxilla; (6) Labium.Scale bars:0.1 mm.

Figures 7-8. Austrolimnius cleidecostae sp. nov. (7-8) Mandibles. (7A, B) Dorsal view of left mandible; (8A, B) Ventral view of right mandible. asp = articulated sclerotized process;lal = lateral lobe;lvs = lateral ventral seta;prt = prostheca;mor = molar region.Scale bars:0.1mm.

Figures 9-10. Austrolimnius cleidecostae sp. nov. (9) Pronotum; (10) Ventral view of ventriteV.Scale bars:0.1 mm.

Figures 11-15. Austrolimnius cleidecostae sp. nov.(11) TergiteVIII,male; (12) TergiteVIII, female;(13) Sternite VIII, male; (14) Sternite VIII,female; (15) Scale-like integument (similar in male and female).Scale bars:11-14: 0.1mm, 15: 0.01 mm.

Figures 16-19. Austrolimnius cleidecostae sp. nov. (16-18) Aedeagus: (16) Lateral view; (17) Ventral view; (18) Spicule of male. (19) Female genitalia. Scale bars:0.1 mm.

Figures 20-24. Distribution records for Austrolimnius cleidecostae sp. nov.(20) Map of Brazil and São Paulo and Santa Catarina states,showing collection localities of Austrolimnius cleidecostae sp.nov.(21-24) Stream habitats of Austrolimnius cleidecostae sp.nov.(21) São Paulo state,São Miguel Arcanjo,Parque Estadual Carlos Botelho (type locality); (22) São Paulo state, Cunha, Parque Estadual da Serra do Mar; (23) Santa Catarina state, Rancho Queimado, Riacho das Antas; (24) Santa Catarina state,São Bonifácio,Riacho Dona Bebê.