Pheraeus guandu Saraiva, Carneiro, Mielke & Casagrande, 2020

Saraiva, Isabella M., Carneiro, Eduardo, Casagrande, Mirna M. & Mielke, Olaf H. H., 2020, A new species of Pheraeus Godman, 1900 (Hesperiidae, Hesperiini, Moncina) restricted to Rio Doce Valley, Brazil, Zootaxa 4859 (2), pp. 285-292 : 286-291

Pheraeus guandu Saraiva, Carneiro, Mielke & Casagrande sp. nov.

( Figs 1– 12 )

Diagnosis. Pheraeus guandu differs from all other species of the genus by the presence of six opaque white spots on the VHW. Almost every other species in the genus shares the presence of spots in the same wing spaces, however, they are never as developed as in P. guandu or present a different color pattern. Phenotypically, the closest species is Pheraeus argynnis ( Plötz, 1884) , whose silver spots are placed beside black spots (in the space M 1 –M 3) or are distinctly flattened (in R s –M 1; M 3 –CuA 1 and CuA 1 –CuA 2) ( Figs. 5–8 ). Male and female genitalia of P. guandu also have diagnostic characters, though very similar to P. argynnis . The male genitalia of P. guandu has a longer and broader anterior projection of the saccus, the costa of the valva is narrower and the coecum of the aedeagus more profoundly bifid. Also, in the female, the lamella antevaginalis is wider, with less developed lateral arms. The lamella postvaginalis has a central patch of microfibrils, similarly to P. odilia odilia ( Steinhauser, 1991) , but absent in P. argynnis .

Description. Forewing length: 7.5–9.5 mm in males (n=7) and 7–8.6 mm in females (n=12). Head: predominantly covered with brown scales; yellow scales scattered from transfrontal suture to clipeolabral suture. Antenna longer than ½ costal margin of forewing, covered by brown scales except in the ventral base of each flagellomeres where the scales are brown. Nudum 13 segments ( Fig. 9A ). Labial palpus quadrate (length equal to width in dorsal view), densely covered by fine and long scales ( Fig. 9C ); first segment short, rectangular; second elongate, about three times longer than first, both covered by a mixture of orange, white and black scales; third segment short, about ¾ of the length of the second, conical, directed upwards, covered by short, compact, dark brown scales. Thorax: dorsal surface mostly covered by long yellowish scales, although some brownish scales also present; ventral surface covered by long brownish scales. Pro, meso and metathoracic legs yellow; midtibiae spined, spurs 0-2-2; tarsus spined. Wings predominantly brown. DFW: three whitish hyaline apical spots, rounded, reduced, partially aligned in the spaces R 3 –R 4, R 4 –R 5, R 5 -M 1; two large spots, whitish hyaline in M 3 -CuA 1 and CuA 1 –CuA 2, the first smaller than the second; a reduced yellowish semi hyaline spot just above 2A; and a diffuse spot of ocher scales below 2A; males with sagittate brown brand (inclined “V” shape—Fig. 9E), upper apex slightly smaller than lower apex, located between CuA 1 –CuA 2 slightly separated from hyaline spot; VFW: predominantly brown, ferruginous in costal area and apical region. DHW: brown, without spots, base of the discal cell with many fine, long, yellowish scales; males with a set of long and thin scale brushes along 2A. VHW: predominantly copper brown, with a distinct brownish band along 2A; discal region with six white and opaque spots: three larger in Sc+R 1 –R S; M 1 –M 3 and CuA 2 -2A and three smaller in R S -M 1; M 3 -CuA 1 and CuA 1 -CuA 2; females with additional black spots at the outer side of the silver spots in spaces M3-CuA 1 and CuA 1 –CuA 2. Abdomen: dorsally dark brown, ventrally gray. Male genitalia ( Fig. 10 ): tegumen convex, wider than long, ventral arm narrow, fused to the dorsal arm of the saccus forming a median triangular thickening where they connect; anterior projection of saccus long (approximately the length of uncus + tegumen) and wide (almost twice the width of aedeagus); uncus base expanded, with lateral short bristles, apex narrow, short and rounded; gnathos hook-shaped in lateral view, with a median membranous patch, sharp and sclerotized apex; valva almost rectangular, costa narrow, sacculus triangular, ampulla narrow, with long rounded bristles projected dorsad, harpe wide with truncated apex and pointed dorsal margin slightly curved towards inner part; fultura inferior V-shaped, projected dorsally around the aedeagus, apex pointed, ventral base with a pair of lateral, short, and rounded anterior projections; aedeagus 1/3 longer than the length of valva, cylindrical, coecum bifid, with short and rounded ends, opening of the ejaculatory bulb of difficult delimitation between the slightly sclerotized dorsal side of the aedeagus, distal opening slightly to the right side of the apex, surrounded by small spines, cornutus absent. Female genitalia ( Fig. 12A ): lamella antevaginalis convex, relatively broad, connected in the middle of the lamella postvaginalis by lateral thin arms; lamella postvaginalis quadrate, median area more sclerotized, T-shaped, with microtriches, apex with reduced central invagination, inner posterior fold well developed and rounded, antero-lateral and basal folds developed, slightly sclerotized and striated; ostium opening wide, antrum conical, long, discontinuous and with membranous area, beginning of the ductus bursae wide in relation to the lamella antevaginalis, membranous, spirally twisted, posteriorly dilated with three bands of multiple small points signa, two laterals and one medial in multiple V shape aspect, bursa copulatrix globular and laterally folded. Papilla analis rectangular, longer than wide, posterior apophyses inserted in anteroinferior portion of the papilla, with an extension equal to the height of the papilla.

Geographical distribution. (Fig. 13) Brazil: Espírito Santo: Baixo Guandu, Itaguaçu and Itapina ; Minas Gerais: Ituêta.

Altitude. 200–600 m.

Type material. Holotype male with the following labels: / HOLOTYPUS / Brasil, Espírito Santo, Baixo Guandú , 2-VI-1970, C.C. T. Elias leg. / Holotype Pheraeus guandu Saraiva, Carneiro, Casagrande & Mielke det. 2019/ DZ 37.459/. DZUP .

Allotype female with the following labels: / ALLOTYPUS / Brasil, Espírito Santo, Baixo Guandu , 10-X-1970, C.C. T. Elias leg. / Allotypus Pheraeus guandu Saraiva, Carneiro, Casagrande & Mielke det. 2019/ DZ 37.569/. DZUP .

Paratypes: Brazil: Espírito Santo, Baixo Guandu , 10-IV-1970, 1 male- em todos; 4-V-1970, 2 female - em todos; 20-VII-1970, 1 m; 20-VII-1970, 1 f; 10-X-1970, 2 m; 10-IV-1971, 1 f; 18-VI-1971, 1 m; 5-IX-1971, 1 f; 11-X-1971, 1 m; 11-X-1971, 1 m; 17-X-1971, 1 f; 28-XI-1971, 1 f; C.C. T . Elias leg., DZ 37.559, DZ 37.549, DZ 37.509, DZ 37.469, DZ 37.519, DZ 37.529, DZ 40.805, DZ 37.619, DZ 37.539, DZ 37.579, DZ 37.479, DZ 37.489, DZ 40.815, DZ 37.559; DZUP. Espírito Santo, Itaguaçu , 18-III-1970, 1 m, C. Elias leg., DZ 37.589; DZUP . Espírito Santo, Itapina , 18-XII-1967, 1 f, Tadeu Elias leg., DZ 37.609; DZUP . Minas Gerais, Ituêta , 24-V-1970, 1 f, C. Elias leg../ DZ 37.499; DZUP .

Etymology. The name refers to the holotype’s toponym, which derives from a very common plant “guandu” at this locality: Cajanus cajan (L.) Millsp. ( Fabaceae ).

Discussion. Pheraeus guandu sp. nov. was recognized at first sight as a new species, based on the very distinct white spots on the ventral hindwings. Thereafter, both male and female genitalia dissections confirmed this new identity. These VHW spots are frequently used as one of the easiest diagnostic characters to differentiate the species in the genus, although some intraspecific variation can be found in their shape and size, as in Pheraeus odilia odilia ( Plötz, 1884) . The genitalia of both sexes present several informative taxonomic and phylogenetic characters, despite the fact that the female genitalia have been neglected, not only in Pheraeus , but also in many taxonomic studies of the Hesperiidae .

So far, Pheraeus guandu sp. nov. is known from a restricted region crossed by the Rio Doce, close to the border separating the states of Minas Gerais and Espirito Santo. Other municipalities relatively close to Baixo Guandú (<150km), such as Linhares and Santa Teresa, were also intensively sampled during a few years but this species was never recorded in these sites (e.g. Brown Jr. & Freitas 2000). The Rio Doce Valley has been extensively transformed in recent decades by agriculture, livestock, and the construction of hydroelectric and tailing dams, thus suppressing most of the local natural landscape.

Recently, two major dam collapses also contributed to natural habitat suppression in Minas Gerais, one of which directly associated with Rio Doce and its gallery forests (FONSECA et al. 2017). However, because no significant sampling effort has been under taken in the region since the 1970s, it is not possible yet to determine whether the species was directly affected by any of these recent habitat changes. Therefore, we here suggest the urgency of conducting new samplings in the region searching for recent records of this species in both protected and unprotected areas.

Figures

FIGURE 9. Pheraeus guandu sp. nov.: A—nudum, C—labial palpus, E—brand. Pheraeus argynnis (Plötz, 1884) B—nudum, D—labial palpus, F—brand. Scale bars represents 1mm.

FIGURE 10. Male genitalia of Pheraeus guandu sp. nov. (A-F) and Pheraeus argynnis (Plötz, 1884) (G-L). A and G—left lateral view of tegumen, saccus, uncus, gnathos, valva and aedeagus; B and H—internal view of right valva; C and I—posterior view of fultura inferior; D and J—dorsal view of uncus and gnathos; E and K—dorsal views of aedeagus; F and L—ventral view of saccus, tegumen, uncus, gnathos, valva and edeagus.

FIGURE 12. A.Pheraeus guandu sp. nov. Geographical distribution.

FIGURES 1–8. Pheraeus guandu sp. nov.: male: 1—dorsal view, 2—ventral view (holotype); female: 3—dorsal view, 4— ventral view (paratype). Pheraeus argynnis (Plötz, 1884): male: 5—dorsal view, 6—ventral view. Brazil, Catas Altas, Caraça, 1-5-II-1985, 1300-1500m, Mielke & Casagrande leg., DZ 40.755 (DZUP); female: 7—dorsal view, 8—ventral view. Brazil, Paraná, Tijucas do Sul, Rincão, 13-II-1969, 900m, Mielke & Laroca leg., DZ 40.775 (DZUP).

FIGURE 11. A. Pheraeus guandu sp. nov.: ventral view of female genitalia. B. Pheraeus argynnis (Plötz, 1884): ventral view of female genitalia.