Tachygonidius paulensis, Vanin, Sergio Antonio & Mermudes, José Ricardo M., 2007

Vanin, Sergio Antonio & Mermudes, José Ricardo M., 2007, Two new Tachygonidius species from the Atlantic coast of Brazil (Coleoptera: Curculionidae), Zootaxa 1415, pp. 57-64 : 61-62

Tachygonidius paulensis , sp. nov.

( Figs.7 , 12 and 13 )

Type-series: Holotype female “Faz. Itaquerê, Boa Esperança do Sul, SP; 21.VI.1965; K. Lenko col.”; “mata ciliar”; “Margem esquerda do r. Jacaré-Guaçu”. Holotype deposited in the collection of the Museu de Zoologia, Universidade de São Paulo.

Description. Body sub-rhomboidal ( Fig. 12 ), about 1.3 times as long as wide (including head), dark reddish brown with narrow black band on pronotum, elytra black with apices dark reddish brown; undersurface of body black, densely clothed with white pectinate scales.

Length (rostrum excluded), female: 4.0 mm.

Head and antennae similar to T. fluminensis .

Pronotum sub-pentagonal, transverse, about 0.7 times as long as wide, with lateral margins rounded; pronotal disc very convex, coarsely and irregularly punctate, except narrow, elongate-oval, black and shiny elevated median space. Sides of prothorax, anterior and posterior angles of pronotum densely clothed with ochreous and white pectinate scales; disc and sides of pronotum also with sparse, long and erect black setae.

Elytra cordiform, slightly wider than long, lateral margins strongly constricted behind humeri; humeri very pronounced and bulbous, feebly depressed on disc, with coarse, deep and confluently punctate striae, and raised discal interstriae; each elytron with one prominent callus formed by confluence of interstriae in front of elytral declivity; elytra with sparse, short to long, decumbent and erect dark ferrugineous setae; sutural interstriae with one row of dark ferrugineous pectinate scales in near basal half, and longer, white to yellowish crossing setae in distal half; the latter margined on each outer side by one row of bright yellow pectinate scales; white pectinate scales forming faint oblique band from elytral margin near posterior coxa to about stria V, and additional yellow or white pectinate scales forming rows or clusters in front of humeri, elytral base, elytral margins, and declivous areas of elytral apices.

Anterior and median legs similar to T. fluminensis . Posterior femora slender ( Fig. 13 ), nearly 9 times as long as wide, width more or less uniform, armed with about 14 small to medium-sized, and 2 to 3 larger teeth. Tibiae elongate-triangular ( Figs. 7 and 13 ), about 3.4 times as long as wide, flattened, inner margin crenulated and weakly arcuate, outer margin with 9–10 conspicuous crenulations, curved and with large, concave notch near apex. Posterior tarsomeres 1–3 with dense brush of light yellow to ochreous setae.

Declivous portion of pygidium oblique and transverse, about 4 times as wide as long.

Etymology: paulensis, Latin , adjective that refers to the state of São Paulo, where the holotype was collected, in the city of Boa Esperança do Sul.

Geographic distribution: only known from the type locality.

Type locality: BRAZIL. São Paulo: Boa Esperança do Sul.

Remarks. Tachygonidius paulensis is very similar to T. fluminensis , for now the only two species of the genus represented in the Atlantic Forest region. The former is easily distinguished from the latter mainly by the pronotal disc very convex (more or less flattened in T. fluminensis ), the elytra strongly constricted behind humeri (weakly constricted in T. fluminensis ), the posterior femora armed with two or three large teeth (with only one large tooth in T. fluminensis ), the entire outer margin of hind tibiae with crenulations (apical twothirds smooth in T. fluminensis ), and the posterior tarsi with a brush of light yellow to ochreous setae (brush of white and yellowish setae in T. fluminensis ).

The two pairs of T. fluminensis available for study permitted description of the sexual dimorphism related to the form of the declivous portion of the pygidium, deeper in the male, and less deep and narrower in the female. The similarly slender pygidium present in the female holotype of T. paulensis suggests that this sexual dimorphism may be shared by all species of Tachygonidius .

Figures

FIGURE 6 – 7. hind left tibia, dorsal view, setae omitted, (6) Tachygonidius fluminensis sp. nov., female paratype; (7) Tachygonidius paulensis sp. nov., female holotype (scale bar = 0.5 mm).

FIGURE 12 – 13. Tachygonidius paulensis sp. nov., (12) habitus, female holotype (length: 4.0 mm); (13) right posterior leg, female holotype.