Thereus vicens Faynel & Fåhraeus, 2023

Faynel, Christophe & Fåhraeus, Christer, 2023, Two new Thereus species from Peru, with notes on ecological niche partitioning (Lepidoptera: Lycaenidae: Theclinae), Zootaxa 5315 (4), pp. 301-314 : 308-309

Thereus vicens Faynel & Fåhraeus , sp. nov.

( Figures 3, 4 , 14 , 19 , 22 , 23 )

Type material. Holotype ♁ ( Fig. 3 ): “ Peru Huánuco // Tingo María // Cueva de las Pavas 730m // 09°22´S – 75°58´W // 7.VII. 2019 // J.J. Ramírez leg.” (white rectangular label, black printed); “LYC 1601” (orange rectangular label, black printed); “Diss. n° 689 // 14.XII.2021 // C. Faynel ” (white rectangular label, black printed); “HOLOTYPE ♁ // Thereus vicens // Faynel & Fåhraeus, 2023” (red rectangular label, black printed). Currently in CF, will be deposited in MUSM.

Paratypes: 1♀, “ Peru Huánuco // Tingo Maria vic // Alt 900 m // 21.VIII.2020 // local/ William leg.”, DNA sample ID CFC22463 ( FILS) . 1♀, Peru, Huánuco, 1500-2000 m, X. 2013, sample ID CF-LYC-1117 ( CF) . Paratypes have the following labels “ Thereus vicens // Faynel & Fåhraeus, 2023 // Paratype ♀ ” (blue rectangular label, black printed) .

Diagnosis. T. vicens sp. nov. belongs to Thereus because it possesses male genitalia associated with dorsal brush organs and the number of antennae flagellomeres (nudum segments) is sexually dimorphic. It is similar to T. illex ventrally. Males differ from other Thereus species by: (1) the DFW scent patch is lacking, while the other species have a DFW scent patch next to the scent pad, (2) both sexes have a characteristic ventral pattern, especially the white VHW straight postmedian line, (3) smaller valvae in ventral view ( Figs 15–19 ), (4) an aedeagus with one cornutus (two in the other species), and (5) a 4.14 % mean genetic distance (COI sequence) with the nearest species, T. columbicola , in the K2P distance matrix (Table 3 and with BIN numbers AEC1746 and ACK2912, respectively).

Description. Male. ( Fig. 3 ). FW length: 17.9 mm (n = 1). Head: Brown eyes sparsely pilose with white circumference; black antennae ringed with white, orange nudum (18 flagellomeres); labial palps white. Thorax: brown with grey scales dorsally, brown and hairy ventrally; legs brown. Abdomen: brown dorsally, beige ventrally. Wings: DFW: basal crescent blue including androconia, costal and outer margin black. VFW: light brown ground color, costa reddish orange at its base. White postmedian band from vein R 2 to CuA 2 bordered basally by a darker brown area. White submarginal band from R 3 to 2A bordered distally by darker brown scales. DHW: largely covered by blue, small reddish spot on anal lobe. VHW: light brown ground color with same pattern as on FW. The white postmedian line forms a W-shaped in CuA 1 –3A and there is a red spot in CuA 1 –CuA 2 and in CuA 2 –2A, the former is distally black pupilled. Brown fringe on outer margin of both wings. Tails at the end of CuA 1 short (0.8 mm) and at CuA 2 long (3 mm), the latter with white tips. Male genitalia ( Fig. 19 ): very large genital ring in ventral view; uncus subrectangular, narrow and setose; gnathos curved, long and thin; tegumen with a ventral projection; vinculum with a dorso-lateral process supporting long dorsal brush organs (secondary sexual organ); but no brush organ attached to lateral part of the vinculum as in the other Thereus species. Valvae very short; saccus also very short (less than two fifth of genitalia length) and pointed. Aedeagus with one cornutus situated at dorsally curved posterior end. Eighth tergite subrectangular ( Fig. 23 ). Female ( Fig. 4 ). FW length: 19.6 mm (SD = 0.33, n = 2). Head: Brown eyes sparsely hairy with white circumference; black antennae ringed with white, orange nudum (27 flagellomeres); Labial palps white. Thorax: brown with grey scales dorsally, brown and hairy ventrally. Abdomen: grey dorsally, beige ventrally. Legs: brown. Wings: DFW: dull blue on a larger part, costal and outer margin dark grey. VFW: beige ground color, costa reddish orange at its base. White postmedian band from vein R 2 to CuA 2 bordered basally by a darker beige area. A finer white submarginal band from R 3 to 2A bordered distally by a darker beige area. DHW: reddish orange spot on anal lobe. VHW: beige ground color. White postmedian line which forms a W in CuA 1 –3A. Submarginal band with white crescents. Small red orange spot in CuA 1 –CuA 2, black pupilled, linked to tornus of same color. Clear beige fringe on outer margin of both wings. Tails at end of CuA 1 short and CuA 2 long, both brown with white tips. Female genitalia ( Fig. 22 ): ductus bursae same length as corpus bursae; ductus seminalis arising from back of the corpus bursae from a pouch in the cervix bursae; large funnel-shaped ostium bursae; signum in corpus bursae absent; no sclerotized invaginations on membrane attached to ventro-lateral sides of papillae anales. It is also absent in T. columbicola and T. eryssus . The association of the sexes was based on similar ventral wing patterns, the same COI sequence and hence the same BIN (AEC1746).

Etymology. This species is dedicated to Jose Vicens, previous owner of the reserve Tierra Linda ( Peru, Cusco, Rio Cosñipata valley), who died in September 2021. It is a noun in the nominative singular standing in apposition to the generic name, not Latinized.

Ethology. Unknown.

Distribution and bionomics. Apparently a mid-mountain species in central Peru, from around 730–2000 m based on available data.

Remarks. As noted by previous authors ( Robbins 1991; Robbins et al. 2015), the pair of ventro-lateral brush organs on the male genitalia that is characterizing the genus (in addition to the pair of dorsal ones) is also absent in Thereus pseudarcula (Giacomelli) . T. vicens sp. nov. is the second Thereus species sharing this particularity. However, these authors warned that the ventro-lateral brush organs could be inconspicuous and may not be detected during dissection. Consequently, more dissections will be necessary to check if this character is really absent in T. vicens sp. nov. since only the holotype has been dissected so far and no other male has been found. The female underside wing pattern shares similarities with Cupathecla gabathana (Strand) but they are dorsally distinct. In Tingo Maria, local collectors sample on an altitude gradient and do not report on the envelopes the exact altitudes, that’s why data in the material is not precise. Two other barcoded male specimens have similar wing pattern (Table 2) but have different COIs sequences and were assigned different BIN numbers on BOLD. These specimens were not included in the type material since they could represent a different species but more material is needed to establish if this is the case (1♁, Peru, Cusco, Quebrada Quitacalzon, 1100m, 1301/7130, 7.XI.2007, Lamas leg., DNA sample ID MHNLXPL1A04 (MUSM), BIN AEO6307; 1♁, Ecuador, Napo, Pimpilala, 20km SSW Tena , 600 m, 08.V.2015, DNA sample ID RCPBXPL1F11 (PB), BIN AER6219).

Figures

FIGURE 23. Male eighth tergite in ventral view.Anterior border (at bottom) W-shape on Thereus tierralinda sp. nov. (left) and subrectangular on T. vicens sp. nov. (right).

FIGURES 1–8. Adults of Thereus, dorsal view at left. 1.♁ T. tierralinda sp. nov. (HT, Peru, MUSM). 2. ♁ T. illex (Colombia, MNHN). 3. ♁ T. vicens sp. nov. (HT, Peru, MUSM). 4. ♀ T. vicens sp. nov. (Peru, FILS). 5. ♁ T. columbicola (Peru, CF). 6. ♀ T. columbicola (Peru, CF). 7. ♁ T. eryssus (Brazil, CF). 8. ♀ T. eryssus (Brazil, CF).

FIGURES 10–14. Male DFW androconia. 10. Thereus tierralinda sp. nov. 11. T. illex. 12. T. columbicola. 13. T. eryssus. 14. T. vicens sp. nov.

FIGURES 15–19. Male genitalia, ventral view (on right), left lateral view (at left). 15. Thereus tierralinda sp. nov. (HT, Peru, MUSM). 16. T. illex (Colombia, MNHN). 17. T. columbicola (Peru, CF). 18. T. eryssus (Brazil, CF). 19. T. vicens sp. nov. (HT, Peru, MUSM).

FIGURES 20–22. Female genitalia. Ventral view (at left), lateral view (middle), papilla analis in lateral view (at right). 20. Thereus columbicola (Peru, CF). 21. T. eryssus (Brazil, CF). 22. T. vicens sp. nov. (HT, Peru, MUSM).