Austrolimnius bocainensis, Miranda, Gustavo Silva De, Sampaio, Brunno Henrique Lanzellotti & Passos, Maria Inês Da Silva Dos, 2012

Miranda, Gustavo Silva De, Sampaio, Brunno Henrique Lanzellotti & Passos, Maria Inês Da Silva Dos, 2012, Two new species of Austrolimnius Carter & Zeck (Insecta: Coleoptera: Elmidae) from Southeastern Brazil, Zootaxa 3389, pp. 14-24 : 21-23

Austrolimnius bocainensis sp. nov.

( Figs.1 c,d–2b,e,h,i)

Diagnosis. Austrolimnius bocainensis sp. nov. has the metasternum with a pair of carinae from the inner margin of mesocoxal cavity to the anterior margin of the metacoxal cavity; cylindrical hind tibiae without any conspicuous concavity or spines. The median lobe and parameres have apices convex at lateral view; the parameres are concave with some setae on inner face and fewer on the external face.

Description. Holotype: male. Total length 2.48 mm; head width 0.43 mm, length 0.40 mm; pronotum width 0.90 mm, length 0.75 mm; elytra width 1.05 mm, length 1.33 mm. Body ( Figs. 1 c,d) short and oval with surface of head, pronotum and elytra dark brown; antennae, mouth parts and legs reddish brown.

Head. Without distinct impressions. Surface with punctures smaller than the facets of the eyes, separated by the distance of their diameter. Small eyes not prominent. Filiform antennae with 11 subequal antennomeres and inconspicuous setae. Clypeus slightly broader and shorter than labrum with anterior margin truncate and lateral angles rounded. Labrum with anterior margin truncate and lateral angles rounded; lateral margins with short pale setae except on the median portion near anterior margin. Maxillary palpus and labial palpus with four and three palpomeres, respectively.

Thorax ( Figs. 1 c and 2b). Pronotum slightly wider than long; anterior margin feebly rounded and narrower than the posterior margin; surface with punctures much smaller than the facets of the eyes, separated by twice their diameter on the posterior half and by their diameter on the anterior half; a pair of complete sublateral carinae present; pronotal disc with a deep and wide median longitudinal impression from the posterior margin of the pronotum (in front of scutellum), to the apex, where it is narrow and shallow. Surface of median impression with punctures similar to those of the pronotal disc. Elytra longer than wide; anterior margin truncate; lateral margin convex and slightly elevated at the apex; shiny surface with seven rows of punctures. First elytral interval inconspicuously raised; third interval feebly convex near the base; fifth interval carinate from base to apex; seventh interval carina reaches the lateral margin at 2/3 from the anterior margin. Epipleura with tomentum and one row of granules slightly larger than facets of the eyes, beginning near the dorsal margin, reaching the ventral margin at the middle of the elytra. Scutellum ( Fig. 1 c) longer than wide.

Prosternum longer than wide. Prosternal process ( Fig. 1 d) wide between legs, with lateral margins converging in a rounded apex. Mesosternum with a deep and feebly wide groove. Median area of metasternum and abdominal segments with a smooth surface, but lateral areas with tomentum and small granules. Metasternum with medial impression on the posterior half, forming an inconspicuous “Y” between the hind coxae. Fore femur with fringe of tomentum on the basal 2/3 on the anterior face; fore tibiae with fringe of tomentum on the apical 2/5 of the anterior face. Middle femur with tomentum similar to that of the fore femur, on the posterior face; middle tibiae with row of setae on the apical half of the posterior face and with spines under tomentum. Hind tibiae with a row of tomentum on the posterior face occupying little more than the apical half, with some spines on the ventral margin; hind tibiae cylindrical without any expansion or concavity; tarsomeres I–IV with some setae on the ventral surface.

Genitalia ( Figs. 2 h, i). Oblong with median lobe and parameres subequal; median lobe pointed at the apex, with an enlarged base; apex of the genitalia slightly curved ventrally; parameres concave with more setae on the internal face than on the external face.

Type material.

Brazil, São Paulo, São José do Barreiro municipality, Serra da Bocaina National Park - Holotype. Male, tributário do Rio Mambucaba, Córrego da Barra Branca, pedra, 07/VIII/2003, Henriques-Oliveira, A.L. leg. ( DZRJ 5572). Paratypes. 1 female, same data as holotypes, cascalho, 07/VIII/2003 ( DZRJ 5575); 1 female, same data, cascalho, 05/VIII/2004 ( DZRJ 5584); 1 male, same data, folhiço correnteza, 5/VIII/2004 ( DZRJ 5574); 1 female, Fazenda Barreirinha, pedra, 07/VIII/2003, Henriques-Oliveira, A.L. leg. ( DZRJ 5579); 2 females, same data, cascalho, 07/VIII/2003, Henriques-Oliveira, A.L. leg. ( DZRJ 5583); 1 male and 1 female, same data, pedra, 06/VIII/ 2004 ( DZRJ 5576); 1 female, same data, cascalho, 06/VIII/2004 ( DZRJ 5571); 1 male, same data, pedra, 05/VIII/ 2004 ( DZRJ 5581); 1 female, same data, pedra, 06/VIII/2004 ( DZRJ 5578); 1 female, same data, folhiço correnteza, 05/VIII/2004 ( DZRJ 5573); 1 male and 2 females, Boqueirão River, 05/X/2007, Henriques-Oliveria, A.L., Baptista, D., Mugnai, R. & Nessimian, J.L. leg. ( DZRJ 5580); 1 male, same data, cascalho, 05/VIII/2004, Henriques-Oliveira, A.L. leg. ( DZRJ 5590); 1 male, same data, VIII/2004, Henriques-Oliveira, A.L. leg. ( DZRJ 5591); 1 male, same data as holotype, folhiço, 05/VIII/2004, Henriques-Oliveira, A.L. leg. ( DZRJ 5592); 2 females, same data as holotype, VIII/2003, Henriques-Oliveira, A.L. leg. ( DZRJ 5593); 2 females, same data as holotype, 07/ VIII/2003, Henriques-Oliveira, A.L. leg. ( DZRJ 5594). Brazil, Rio de Janeiro, Nova Friburgo municipality - 1 female, Macaé de Cima, afluente de 2ª ordem do Rio Macaé, Armadilha luz U.V., 29/XI/2008, Ferreira-Jr, N., Jardim, G.A., Gonçalves, I.C., Sampaio, B.H.L., Alecrim, V.P., Santos, A.P.M. leg., ( DZRJ 5585); 1 female, Lumiar, tributário do Córrego Santiago, 28/VIII/2001, Nessimian, J.L., Humantinco, A.A. leg, ( DZRJ 5586); 1 specimen, Lumiar, Rio Boa Esperança, córrego de 3ª ordem, 22º 23' 57,9"S 42º 19' 14,6"W, 583m, 15/XI/2008, B.H.L. Sampaio, leg., ( DZRJ 5587); 8 specimens, Rio Macaé, Macaé de Cima, 22º 25' 30,6"S 42º 32' 00,7"W, 977m, 13/IX/2009, J.L. Nessimian, I.C. Gonçalves, B. Clarkson, A.L.A. Pimenta, V.P. Alecrim, A.P.M. Santos leg., ( DZRJ 5588); 7 specimens, Rio Macaé, Macaé de Cima, 22º 24' 46,0"S 42º 31' 16,2"W, 935m, 01/XII/2008, B.H.L. Sampaio leg ( DZRJ 5589).

Etymology. The species name ( bocainensis ) is a neolatinized adjective of the type locality (Serra da Bocaina National Park).

Comparative notes. Austrolimnius bocainensis sp. nov. has a short and oval body shape, which is similar to almost all species of Austrolimnius . The new species is included in the group of species with one row of epipleural granules ( A. laevigatus , A. pilulus and A. uncatus sp. nov.), and among these species, A. bocainensis sp. nov. can be easily differentiated by the shape of the hind tibiae: A. bocainensis sp. nov. has a cylindrical hind tibiae, without any expansion or spines; A. uncatus sp. nov. has the hind tibiae with an expansion at the medial portion with spines on the distal half; A. laevigatus has an expansion at the median portion with a concavity on the distal margin with spines; and A. pilulus has an expansion at the basal 2/5 with a smooth concavity on the posterior border. Additionally, A. bocainensis sp. nov. does not have setae on the mid-tarsus, which are present in A. laevigatus , A. pilulus and A. uncatus sp. nov. The male genitalia of the new species is very similar to those of A. laevigatus and A. pilulus because all of them have the parameres and median lobe of subequal length. But, some differences are notable on the shape of the median lobe: A. bocainensis sp. nov. has the apical fifth pointed and the basal fourth enlarged; A. laevigatus has the median lobe tapering to the apex from its middle; and A. pilulus has a subcylindrical median lobe with a slight curve in ventral direction at the apex. The male genitalia of A. bocainensis sp. nov. and A. uncatus sp. nov. can be easily differentiated because A. uncatus sp. nov. has its characteristic hook-like genitalia.

With just one row of epipleural granules, Austrolimnius bocainensis sp. nov. is easily distinguished from species with two rows of epipleural granules ( A. eris , A. formosus and A. pusio ). Two other differences can be observed between A. bocainensis sp. nov. and A. formosus , they are the body shape, which is short and oval in the new species and fusiform in A. formosus ; and the relation of the parameres to the median lobe, which are subequal in A. bocainensis sp. nov., while in A. formosus the parameres are much longer than the median lobe. Austrolimnius eris and A. pusio can be distinguished from A. bocainensis sp. nov. by the absence of a longitudinal impression on the pronotum, a character that is present on A. bocainensis sp. nov.

New records for Brazilian Austrolimnius . Since the description of Austrolimnius species from Brazil by Sharp (1882), Grouvelle (1888) and Hinton (1941 and 1971), no additions to the Brazilian species of the genus were made, either with new records or with new species. Almost 40 years later, Passos et al. (2009) presented new records for two species, A. laevigatus and A. pilulus , for Rio de Janeiro state. We further increase the knowledge of this genus’ distribution in Brazil by reporting new records for three Austrolimnius species ( Fig.5 ): A. formosus from Rio de Janeiro state (Angra dos Reis, Cachoeiras de Macacu, Casimiro de Abreu and Nova Friburgo municipalities); A. laevigatus from São Paulo state (São José do Barreiro municipality); and A. pilulus from other municipalities from Rio de Janeiro state (Angra dos Reis, Casimiro de Abreu and Nova Friburgo) and from São Paulo state (São José do Barreiro municipality) ( Fig. 5 ).

Figures

FIGURE 1. Austrolimnius uncatus sp. nov. a—Dorsal habitus. b—Ventral habitus; the arrow on the left indicates the spines on the hind tibiae, and the arrow on the right indicates the fine long setae of the middle tarsus. Austrolimnius bocainensis sp. nov. c—Dorsal habitus. d – Ventral habitus (Scale bars: 1 mm).

FIGURES 2. a— Austrolimnius uncatus sp. nov. dorsal view of pronotum. b— Austrolimnius bocainensis sp. nov. dorsal view of pronotum. c— Austrolimnius uncatus sp. nov. mid-tarsus. d— Austrolimnius uncatus sp. nov. hind tibiae. e— Austrolimnius bocainensis sp. nov. hind tibiae. f and g — Austrolimnius uncatus sp. nov. male genitalia: f—Ventral view. g—Lateral view. h and i — Austrolimnius bocainensis sp. nov. male genitalia: h—Ventral view. i—Lateral view. (Scale bars of figures f, g, h and i: 0.1 mm)

FIGURE 5. Distributional map of the Brazilian Austrolimnius.