Bidessodes

Braga, Rafael Benzi & Ferreira-Jr, Nelson, 2009, Three new species of Bidessodes Régimbart (Insecta, Coleoptera, Dytiscidae) from the Amazon river floodplain, Zootaxa 2034, pp. 43-48 : 44

Bidessodes (s. str.) nessimiani Braga & Ferreira-Jr., new species

( Fig. 1 )

Diagnosis. Elytra light brown with darker longitudinal fasciae ( Fig. 1 a). Prosternal process parallel-sided and with rounded apex ( Fig. 1 b). Middle tibiae curved in males. Last visible sternite without carina or sulcus ( Fig. 1 c). Aedeagus in lateral view narrow and angulate before apex ( Figs 1 d–f). Parameres in dorsal view parallel ( Figs 1 d, e).

Description. Holotype male: total length 2.50 mm; maximum width 1.1 mm; maximum length of the head 0.38 mm; elytral length 1.72 mm; maximum width of the pronotum 0.96 mm.

Body fairly oblong with lateral margins subparallel, slight angle present between pronotum and elytra; surface covered with shallow and fine punctation; pubescence consisting of numerous metallic, iridescent setae; setae denser on pronotum and elytra ( Fig. 1 a). Cervical region smooth, without punctures, setae, or stria. Pronotum with basal striae and without transverse furrow; prosternal process with lateral margins parallel and apex rounded ( Fig. 1 b). Legs with three basal tarsomeres expanded on fore and middle tarsi; middle tibiae curved near base; coxal lines raised and parallel. Elytra without striae, sutural lines or rows of punctures; epipleurae without transverse carina. Last visible sternite without carina or sulcus before apex ( Fig. 1 c). Aedeagus in lateral view narrow and angulate before apex ( Figs 1 d–f). Parameres in dorsal view parallel, visible from middle of aedeagus (holotype has left paramere detached from aedeagus) ( Figs 1 d, e).

Coloration. Head and pronotum light brown. Elytra light brown with dark brown longitudinal fasciae; lateral and mesal fasciae discontinuous; sutural fascia continuous, from which arises three transverse stripes, basal stripe joining all fasciae, mesal and subapical stripes joining sutural and mesal fasciae, lateral fascia and subapical stripe darker in color; apical spot dark ( Fig. 1 a). Venter uniformly yellowish-brown.

Variation. Measurements of the body can vary in total length 2.24–2.62 mm; maximum width 1.02–1.12 mm; maximum length of the head 0.26–0.38 mm; elytral length 1.57–1.78 mm; maximum width of pronotum 0.90–0.96 mm. The elytral color pattern can show some variation in the pattern of dark brown fasciae and spots, in some individuals the fasciae and spots are darker and slightly merged, mainly the sutural and mesal fasciae. In females, the middle tibiae are straight at the base.

Type material. Holotype 3, INPA (Coleop Holotipo INPA 303): Brasil, Amazonas, Tefé, São João do Catuaí, Lago da Piranha, 11/09/2003, -3.62524, -64.18968, Nessimian J. L. & Hamada N. Paratypes, INPA (Coleop Paratipo INPA 303 [1–121]): 13 Brasil, Amazonas, Tefé, São Francisco da Boca da Capivara, Igarapé, 09/09/2003, -3.36102, -64.67915, Nessimian J. L. & Hamada N.; 93 13Ƥ Brasil, Amazonas, Tefé, São Francisco da Boca da Capivara, Barra do Solimões, 09/09/2003, -3.28228, -64.62169, Nessimian J. L. & Hamada N.; 163 16Ƥ Brasil, Amazonas, Tefé, São Francisco da Boca da Capivara, Barra do Solimões, 09/09/ 2003, -3.28228, -64.62169, Nessimian J. L. & Hamada N.; 13 Brasil, Amazonas, Tefé, São João do Catuaí, Lago da Piranha, 11/09/2003, -3.62524, -64.18968, Nessimian J. L. & Hamada N.; 323 33Ƥ Brasil, Amazonas, Codajás, Urucurizinho, Lago Cuxuará, 15/09/2003, -3.97121, -61.96065, Nessimian J. L. & Hamada N. DZRJ: ( Coleoptera 2817 ) 243 22Ƥ Brasil, Amazonas, Codajás, Urucurizinho, Igarapo 15/09/ 2003, -3.96160, -61.95125, Nessimian J. L. & Hamada N.; ( Coleoptera 2818 ) 123 34Ƥ Brasil, Amazonas, Codajás, Urucurizinho, Lago Cuxuará, 15/09/2003, -3.97121, -61.96065, Nessimian J. L. & Hamada N.; ( Coleoptera 2819 ) 2Ƥ Brasil, Amazonas, Ilha da Paciência, Nossa Senhora da Conceição, Lago Jacitara, 18/ 09/2003, -3.27798, -60.27626, Nessimian J. L. & Hamada N.

Etymology. The species is named for Dr. Jorge Luiz Nessimian, one of its collectors.

Taxonomic notes. Bidessodes nessimiani sp. nov. shares with B. demarcoi sp. nov. and the Amazonian species B. charanicu s an overall similar color pattern consisting of darker longitudinal stripes on a lighter background. However, B. nessimiani sp. nov. can be separated from other Bidessodes species by the combination of the following features: presence of a sutural longitudinal dark fascia, absence of a sulcus on the last visible sternite, and by the form of the male genitalia.

Figures

FIGURES 1 – 3. 1. Bidessodes nessimiani sp. nov. 2. Bidessodes hamadae sp. nov. 3. Bidessodes demarcoi sp. nov. a, Dorsal habitus; b, prosternal process, ventral view; c, last visible abdominal sternite; d, aedeagus and parameres, dorsal view; e, aedeagus and parameres, lateral view; f, aedeagus, lateral view. Scale in dorsal habitus = 1.0 mm, others = 0.5 mm.