Description of Robinsonia maranhensis Laguerre, sp. nov.

(BIN = BOLD:AAM8552) Fig. 9.

Holotype. ♀, BRAZIL, Marañhao, Acailandia: Reserva Biologica Integral de Gurupi, 17-IV- 2010, 275 m, -4.0014° -46.8372°, Gen. ML 3209 (light-blue manuscript label).— Sample ID BC-INCT0985—BOLD Process ID INC- TA985-10 (yellow printed label), T. Decaëns leg.— Will be deposited in MPEG.

Holotype female description (Fig. 9). Head and thorax. Antennae shortly bipectinate, shaft and rami brown, greyish beige at base, scape whitish. Frons dirty white, vertex pure white. Patagia, tegulae and thorax, white. Palpi dirty white underside, yellowish upper side, third segment very short.

Legs. Anterior coxae pure white. First pair of legs light brownish grey. Second and third pairs dirty white below with a brownish grey upperside.

Forewing. Wings rounded with a straight termen, entirely silky white. The costa up to the apex is covered by a narrow black line bordered inside by a greyish line. Below similar to upper side but the costa very narrowly black at base then widening toward apex, bordered internally by dirty greyish white until the cell.

Hindwing. Rounded wings entirely silky white. Underside similar to upper side.

Abdomen. Silky white and hairy upper side and creamy yellow underside.

Forewing length: 16 mm (n = 1).

Male: unknown.

Female genitalia (Fig. 10A–C). Papilles anales subrectangular, concave in middle. Apophyses very thin, the anteriores shorter than the posteriores. Pheromone glands tubular. Antrum slightly sclerotized shaped as a flat “U”. Ductus bursae as a flat ribbon, sharply bent near extremity and with a narrow fold in middle. Bursa copulatrix hemispherical entirely covered with tiny spicules. In the last third two small circular and concave signa.

Early stages. Unknown.

Etymology. Named by reference to the original locality: Marañhao.

Distribution. Presently only known from the Marañhao state, near the border with Parà, an area with a largely endemic fauna.

During the past 10 years I have received from Ulf Drechsel (Paraguay) some scattered specimens of a small whithish inconspicuous Arctiinae which identification proved to be very difficult. Finally three specimens (2 ♂ 1 ♀) were sequenced and, to our surprise, the sequences nicely align within the genus Robinsonia not far from Robinsonia klagesi Rothschild, 1910 (7.8 %) or Robinsonia mossi Rothschild, 1922 (5.7 %), two well known species present in French Guiana but with totally different habitus (see Fig. 3). The male and female genitalia confirm this classification and this species is described below as new under the name Robinsonia drechseli Laguerre sp. nov.